Thursday, February 18, 2021

Blizzconline Leak: Chains of Domination and BC Classic

 Well, I've got to imagine it sucks when something this big that you've been working on leaks online. Still, with the info out there, I have to say I'm pretty excited about what this entails.

As a big old disclaimer: none of this is official, and while I think it's unlikely for much of it to change, given how soon Blizzconline is happening, this is still stuff that Blizzard has not pulled the trigger on announcing.

This is coming from MMO-Champion's main page, so it's a pretty reputable source.

If you want to let the announcements speak for themselves, I'll put a spoiler cut here:

What Does 5E D&D Need?

 This year will see the 7th anniversary of 5th Edition Dungeons & Dragons. It's the most popular edition of the game ever, bringing in legions of new players (myself included).

The exact history of all the editions is a little complex, but my basic understanding is that you had the original first edition and then Advanced Dungeons & Dragons (a sort of revision to that first edition) that lasted from the 70s inception of the game through the 80s (the edition the kids in Stranger Things are playing is, I believe, AD&D) while 2nd Edition proper launched in 1989, and would be the "modern" edition of the game through the 90s. 3rd edition launched in 2000, with a heavy revision called 3.5 that came in 2003. Then, in 2008, 4th edition came out. This one I think was less popular, and so they announced their work on 5th edition in 2012, with a 2014 release.

Presumably, there will at some point be a 6th Edition. But I do wonder a bit about whether we're really itching for such a shake-up.

Indeed, we don't really know what a 6th Edition would look like - I've never gone through an edition changeover, but I think a fair number of systems can either be replaced or seriously changed. I see a lot of older players who often get tripped up by things like ability checks versus saving throws (something that in 5th edition look very similar to one another but are importantly distinct rules-wise).

Given 5th Edition's popularity, though, I don't think they're in a rush to move past it. But I do think that there are some new things they might need to look into when it comes to publications.

One thing I think we can expect to be constant is adventure books. While I've never been as eager to DM a published adventure as I have been to simply run my own, for many people this simply is how D&D is played - you run a character through the latest book and wait for the next or just run Curse of Strahd again because it's just so freaking good.

Adventure books are fun, and even as someone who likes homebrew campaigns in homebrew worlds, I'll often get them more for inspiration than anything else (also I feel like if I ever have kids, or perhaps ever become a cool uncle, I could dazzle some little ones with this treasure trove.) But, apart from some new items (that often play directly into the adventure's specific story) and monsters (likewise,) they don't tend to really add anything permanent to the game that could be used in other contexts.

The core three books are generalized to work for any setting - the DMG even has suggestions on how to build a setting that might be quite different from the Great Wheel cosmology that is the default. We've had four books that add to this.

Two are monster books - Volo's Guide to Monsters and Mordenkainen's Tome of Foes. For the most part, these can be seen as expansions to the Monster Manual. However, while the MM is perhaps the most straightforward book in the edition - it's monsters, monsters, and monsters, and not really anything else - these two also spend a lot of time on lore as well as throwing in some player options like playable races.

Two are more general rules-expansions. Xanathar's Guide to Everything and Tasha's Cauldron of Everything have less of a central focus. Probably the closest thing to a focus for them is the additional subclasses they add to the game (and in Tasha's case, reprinting a whole class introduced in the Eberron campaign setting book in a setting-agnostic format.)

If I were to advise an ambitious newcomer that had the same goals that I did when I started playing the game on what books to buy, I'd tell them to obviously start with the core three, and then get these four next (and, again, possibly Curse of Strahd as a suggestion on how you can build a campaign.)

The campaign setting books are my next-favorite releases, because of the broad possibilities they offer.

But I also wonder if there aren't some types of books we could see that would bring in something 5E is missing. What, then, are we missing?

The first, and most obvious, I think, is guidance on building adventures for high-level characters.

Mordenkainen's went out of its way to give us lots of monsters with high challenge-ratings. We got many Archdevils and Demon Lords who can serve as campaign bosses, but also plenty of more generic statblocks that nevertheless represent very powerful creatures - like a Drow Matron Mother, one of the most dangerous humanoid stat blocks that exist.

Still, I think that there could be better guidance on building adventures featuring such creatures. Consider, for instance, that a Lich is a classic main-villain. With a CR of 21 (or 22 in a lair), a Lich on its own is meant to be an appropriate challenge, according to Xanathar's encounter-builder, for a 6-player party of 16th-level characters.

But a Lich has, on average, 135 health. Yes, it's got spells like Finger of Death and Power Word Kill, but I guarantee you that if it rolls crappily on its initiative, 6 level 16 characters are going to tear this thing apart before it gets off any of those spells, even with legendary actions.

So rather than just throwing high-CR monsters at the party, having a book about strategy and building encounters and challenges that will make your villains feel like real threats without simply being overpowered stat-wise compared to your party would be really cool (in Descent into Avernus, when I played, our level 11 characters were able to beat Yeenoghu for real before we could be saved by cutscene magic, as is intended in the adventure.)

I want a book called Vecna's Guide to Villainy. Give us things like dynamic encounter spaces (I find that players really enjoy dealing with crazy fight locations) and even suggestions on how a villain can use suites of spells to give the heroes a hard time (Nystul's Magic Aura looks pointless from a player's perspective, but consider that your lich can cast it along with some illusion magic so that the evil-sensing paladin will think that the lich is just a friendly old wizard.)

Next:

I'd love to get some guides to planar adventures. This actually winds up working well as another "high level play" book, given how spells like Plane Shift, Etherealness, and Dream of the Blue Veil start to become available to higher-level players.

A 5th-edition guide to the outer planes would be a lot of fun (and allow a Planescape book to focus more on Sigil and the Factols). Likewise, I actually really love that the various D&D settings take place within the same multiverse - just as I'm trying to build up to a planes-hopping leg of my Ravnica game, I'd love to have some guidance on building an adventure that would, for instance, have the players travel between the Forgotten Realms and Greyhawk and Dragonlance.

Overall, as I write this, I think the general vibe is that 5th Edition runs very well in tiers 1 and 2. When you get into tier 3, it becomes harder to challenge your party thanks to the power that becomes available to you. Unfortunately, I feel that the general response has been to have most adventures/campaigns end around those levels. But those high levels are supposed to be the reward for sticking with characters for so long - not that it isn't fun, but surely when you chose to play a wizard at level 1, you envisioned that character eventually commanding crazy, world-bending magic - the sort of thing that doesn't become available until the later levels.

With so many people playing and with years of familiarity with the 5th edition rules, I think that pushing things into higher-level play with some publications that help fine-tune such adventures would be really cool and welcome.

Wednesday, February 17, 2021

Superheroism and D&D

 I am certain there is some sort of superhero-based TTRPG out there. But I have been watching a ton of video essays on YouTube analyzing the MCU (don't judge me) and on top of that, I find myself eagerly dreaming of some hypothetical future campaign in which I will play an Armorer Artificer and try, somehow, to not just make it feel like Iron Man, whom the subclass is about 90% based on.

I've been thinking a lot about DM'ing from a sort of theoretical and philosophical point of view. My Ravnica game is ongoing, and while there are a lot of things that I'm looking forward to getting to in that campaign (the player characters all have latent planeswalker sparks, so come level 13-15ish we're going to start hitting other MTG planes) I have also been thinking about how I want to build my next campaign.

While the crux of that plan is to try to build the villains and obstacles of the campaign around what the players write into their backstories, I've also been giving some thought to other ways campaigns could work.

Today, I had probably my most ambitious idea, which is not just a campaign but also a kind of hack into the game itself.

Let me back up and talk about how I got here:

One philosophical thing I believe I've written about on this blog is the notion of scaling. Generally speaking, the game runs smoothest when the challenges you face are scaled to the players' abilities. You don't have them fight a Lich at level 2, and you don't have them fight Displacer Beasts at level 17.

But there's also something that feels almost dishonest about that. Elder Scrolls: Oblivion is an open-world RPG that shares a lot of its aesthetic with D&D. Its predecessor, Morrowind, had the following problem: the open world meant that there wasn't a ton of direction given to the players, and there were certainly no physical barriers, which meant that a new character could easily accidentally wander into areas they weren't suited for and just die. This also meant that if you wanted to play though and built your character's power, you did have to stick to particular routes through the game.

Oblivion, however, introduced the idea of level scaling: basically, as you got more powerful, the things you encountered in the world got more powerful. But this had two nasty consequences. The first was the absurd - those bandits on the road, pushed to crime out of desperation, were now armed with glowing, magical weapons that they could probably sell for enough money to live out the rest of their days in comfort. The other, bigger problem was that leveling up - becoming more powerful - actually made you relatively weaker to the rest of the world unless you had built your character extremely carefully.

The power treadmill makes you feel like you're stuck in place if you're never given a chance to feel that power.

How does this get to superheroes? I'm getting there.

It varies from setting to setting, but I think the general premise of D&D is, or at least should be, that adventurers are exceptional. While a 1st-level Fighter isn't actually much stronger than a "blank" stat block that just has the attack action, the lore of what it means to be a "Fighter" in a D&D world is that you have exceptional skill and training. While the class name is weirdly simplistic and could arguably be applied to any of the classes (World of Warcraft's rough equivalent is the Warrior, which I think is a far better class name) in a D&D world, a garrison of soldiers will feel a wave of relief when the top brass send in a Fighter to lead their charge.

It's a bit of a disconnect - after all, all a level 1 Fighter can do that a standard NPC with decent armor and weapon proficiencies can't is take a moment each short rest to take a deep breath and recover some of their hit points. On the other hand, you could imagine that taking a spear to the gut that would at least knock out the average soldier and just walk it off would make you a legendary hero before you get into the numbers inflation of D&D.

Consider two different scenarios: one, the party is visiting a city to talk with some quest NPCs, maybe spend some of their earned gold, and do some downtime activities. In that case, as a DM, you'd probably be happy to let the guards they encounter simply use the "Guard" stat.

In the other scenario, the party is trying to sneak into the city of a foreign power hostile to their homeland, hoping to recover some stolen magic item or fight the monster the evil emperor has in the dungeon beneath his palace. In that case, as a DM, you'd be tempted to make the guards of this city all elite veterans with high passive perceptions to spot any intruders.

But you probably shouldn't. The guard stat block is meant to represent your rank-and-file individual hired to patrol the streets and deal with petty thieves. And that's who would be patrolling the streets of that city.

Essentially, there should be a scarcity of power in order for that power to feel significant.

And that's where we get to superheroes.

See, if your cities are guarded entirely by beefy, 150 HP, plate-armored killing machines with 20 strength and three attacks per round, then why the hell would the kingdom actually be worried about giants or dragons or any of that stuff?

The player characters might need to work at it a bit - they might need to level up and learn their abilities better - but by being a member of one of the various character classes, they contain that potential for up to 20 levels of progression, and that makes them exceptional even early on... but especially once they're a bit farther along.

Their exceptional power - and it's exceptional because of its rarity - means that their actions become important in the larger landscape of the world. You know... like a superhero.

The classic form of the superhero story is that of the crime-fighter. Superman, Batman, Spider-Man - the early comics tended to have them stop bank robberies and such. It's really not unlike how a low-level D&D group will cut their teeth fighting goblins (usually bandits) or... bandits, or kobolds (again, usually bandits.) With Batman, the individual gangs and bank-robbers aren't any better-equipped than the police, but the police are overwhelmed by the amount of crime and internal corruption stymying their efforts to do their jobs.

So, Batman, whose exceptional skills both as a martial artist and with all of the unusual gadgets at his command, can more efficiently and easily (and safely) fight crime. As a single person, he can supplement the overloaded law enforcement of Gotham.

But that's just how it starts. Indeed, the Joker in The Dark Knight more or less states his motivation as a desire to up the stakes - with Batman putting your old-fashioned criminals behind bars, he wants to become (and create) villains who can prove a match for Batman. And thus, the mundane system that was having difficulty managing things in normal times is now utterly unprepared when something truly, again, exceptionally powerful emerges as a threat - the superhero is needed all the more, because now Batman isn't just sharing the weight of responsibility - he becomes the only one who can bear it.

And there are the parallels: if you commit to your NPCs retaining ordinary stat blocks, your players will soon become their only hopes. If a full-on Vampire arrives in a city and wants to take it over, the Noble who rules the city ain't going to stand a chance. They need the party: the superheroes.

Ok, this has been just a conversation about the parallels between superhero fiction and D&D. But let's now get into the sort of hack I'd present.

I think that the existing six ability scores are pretty good and nearly universal for use in TTRPGs. My, perhaps controversial, suggestion is that the character classes also need not change (this also simplifies things given the amount of rules complexity written into the classes and their many subclasses.)

However, the superhero genre (which is admittedly a meta-genre that can encompass many things) does have different aesthetics than D&D. Perhaps most obviously, there is the fact that D&D's system of character race is drawn very much from Tolkien. Meanwhile, in the superhero genre, the majority of superheroes are human (with many notable exceptions, including the OG superhero himself, Superman.)

Superheroes thrive on uniqueness, even though there is a lot of conceptual overlap between existing superheroes. Part of their exceptionalism is that they tend to have some kind of exceptional origin. Rather than using "race" as a thing, I'd replace this with "origin." Origin would refer specifically to the origin of their powers. For instance, Tony Stark/Iron Man would have an Origin of "Super-Science," because his powers are derived from his genius as an engineer, allowing him to build his suits. But lest you think that that would just mean "Artificer," another "Super-Science" Origin character would be Bruce Banner/The Hulk. His character class would most certainly be Barbarian, given that it is his rage that transforms him and empowers his abilities, but the origin of that power is still scientific experimentation. Thor, on the other hand, might also be a Barbarian (Storm Herald) (though I'll confess that it's a bit hard for me to figure out just what he is - Eldritch Knight Fighter? Storm Sorcerer? Tempest Cleric? Enhancement Shaman?) but his Origin would be something like "Mythic Heritage," tying his powers to a divine, supernatural source, because, you know, he's a god.

Origin would come with some suite of minor features, like race does. It might also come with some skill proficiencies (though some races already do).

Backgrounds would likely be more or less functionally the same - it's easy enough to create new backgrounds to fit a modern superhero setting. Again, for instance, you could give Iron Man the "corporate executive" background while Bruce Banner has the "academic" background (so... Sage?).

The other tweak I might play around with is weapons. Superheroes are really into punching things, for one, so I might revise the rules for unarmed strikes or maybe give certain classes reasonably powerful unarmed strikes inherently. Also, given that superheroes that use weapons tend to have pretty iconic ones, I might focus on, rather than replacing weapons with cool new ones, have a system by which a weapon gets upgraded over the course of the campaign. (Alternatively, have the player start with a very powerful weapon - another thing that makes them exceptional.)

Unless you have players who are into solo-campaigns, you're probably going to have to have the team do an Avengers/JLA/X-Men team-up from the get-go, but the existence of such groups (the Fantastic Four, the Guardians of the Galaxy...) means it's not hard to have it stick to the genre that way.

Saturday, February 13, 2021

Zealot Barbarians Get Very, Very Hard to Kill

 One of campaign 2's characters on Critical Role is Ashley Johnson's Yasha. Yasha is an Aasimar Barbarian, and her subclass is Path of the Zealot. And while that is a show that sets the stakes pretty high pretty frequently, I think you're going to be hard pressed to actually see Yasha die at any point, at least in a combat situation.

Zealot's not new - it was introduced in Xanathar's Guide to Everything. While you can, sort of, play it a bit like a Barbarian's version of a Paladin, given that it's a subclass built on devotion to some divine entity, the Barbarian aspect of it is quite strong - flavor-wise, it fits very strongly with chaos rather than law (and while there's no longer any rule that Paladins have to be lawful, the class flavor certainly leans that way in most cases.)

Indeed, there's nothing that says you even have to be following a good deity. Your Orc Barbarian might be devoted to Gruumsh, for instance.

Let's talk about what the Zealot gets, though spoiler alert: the level 14 capstone is the thing I'm most blown away by. Still, the other features are good.

At level 3, when you choose the subclass, you get two features: Warrior of the Gods and Divine Fury.

The former is mostly flavorful, but can potentially be a life-saver when your party doesn't have the funds to get a bunch of revivify diamonds - basically, resurrection magic doesn't need a material component to bring you back. As long as your Cleric has a 3rd level slot, you're good.

Divine Fury will be a more frequently-used thing. Once per turn, when you hit, you get to deal an additional 1d6 plus half your Barbarian level damage when you hit with an attack. You choose when you pick this subclass if the damage is radiant or necrotic - I imagine the idea is that good deities will do radiant while evil ones do necrotic. It's too bad that radiant tends to be more useful in more cases, so I imagine most will choose that. This is a pretty nice boost to a Barbarian's already respectable damage output.

At level 6, you get Fanatical Focus - while raging, you can reroll a failed saving throw to try to succeed. You get to do this once per rage. While I can tell you that I don't think I've ever turned a failure into a success with my Fighter's similar Indomitable feature (he's pretty hyper-specialized on the three ability scores he need for core features - Strength, Int, and Con) this is still a good Hail Mary to use if someone tries to dominate you.

At level 10, you get Zealous Presence. As a bonus action, you can give yourself and up to 10 allies (so  the vast majority of adventuring parties) within 60 feet of you advantage on attack rolls and saving throws until the start of your next turn. It's a pretty nice buff to the party that can make the first (well, second, as you'll probably want to rage on the first one) round of combat go a bit better.

However, now we come to the crazy one:

At level 14, you get Rage Beyond Death. Hitting 0 hit points doesn't knock you unconscious if you're raging. And while you'll still get failed death saves from taking damage at 0 hit points, you cannot die until the rage ends. And then, you only die if the rage ends and you have 0 hit points.

Which is freaking crazy.

While I think a DM could rule that if you take massive damage (i.e. taking enough damage to put you at "negative your max health") that might kill you anyway, but then, you're a Barbarian, so that's going to have to be an utterly enormous amount of damage. Likewise, I could imagine ruling something like Disintegration could also kill you despite this. But still, in the vast majority of situations, you're basically unkillable.

Consider that this comes after Relentless Rage, which allows you to make Con saves (with a rising DC each time, resetting on a long rest) to avoid dropping to 0 hit points, and then that at the next level's Persistent Rage, your Rage only drops after the full minute is up, if you end it yourself, or if you fall unconscious (which you won't be, because of Rage Beyond Death,) and you become basically invincible for a minute every time you rage. (And given that the language on Relentless Rage does account for massive damage, which could be read to say that Rage Beyond Death then does not even allow you to die from that, you really cannot die.)

The image here is astounding - you could be burned to a crisp, half your skull exposed, and actively on fire, but you're just so profoundly unrelenting that you still fight. And man, isn't that what you're going for with a Barbarian?

Also, remember that even if you have three or three hundred failed death saves while raging, as long as you get any healing whatsoever before your rage drops, you don't die.

Bringing this back to Yasha: she's an Aasimar. Which means that she has a once-a-day touch-range heal that restores HP equal to her level.

So she could be basically dead, but spend her full minute carving up whatever horrifying demons or aberrations they're facing, and as long as she taps herself on the shoulder and uses Healing Hands before that minute is up, she's going to walk away from that fight.

Thursday, February 11, 2021

An Artificer's Guide to Siege Weapons

 So, I love the Artificer. I love the concept, the class features, the flavor, and the overall execution. Yes, I realize I should probably play a pure caster that isn't a Warlock at some point (it'd be nice to cast high-level spells one day,) but I'm extremely drawn to the artificer.

I did some table-napkin math today and came up with something awesome that an artificer could do if they needed to besiege a castle.

Ok, couple prerequisites:

You need a party with at least five friends in addition to the artificer.

You need a catapult.

You need a 20-foot block of granite.

And you need to be level 11 or higher.

Artificers get a potentially game-breakingly good ability at level 11: spell storing item. You can imbue an item with a single spell of 1st or 2nd level that takes on action to cast. The item has charges equal to twice your intelligence modifier (likely 10 by level 11,) and while it uses your spellcasting ability for its attack bonus or save DC, anyone can use the object, and that person maintains concentration if the spell requires it.

Now, you make one of these things with enlarge/reduce in it.

Ok, you've used some means to bring this massive cube to the battlefield - maybe your wizard teleported it there or something. (Teleport requires an object fit in a 10-ft cube, but we already have enlarge/reduce, don't we?)

Now, you set up your catapult to launch its payload at the enemy castle. You and your five friends cast the reduce side of enlarge/reduce on the cube of granite, reducing it from gargantuan to huge, huge to large, large to medium, medium to small, and small to tiny. The cube's weight is reduced to 1/8th of its normal weight each time it's reduced, so after five castings, you've reduced this thing to .003% of its usual weight. Given the density of granite, that makes it about 7.5 inches on a side, and it weights about 41 pounds. That's not light, exactly, but it's well within the normal payload of a catapult.

You don't have long, but you get this cube into the catapult and then let 'er rip. While the thing is flying in mid-air, everyone drops concentration, and this 41 lbs cube expands into a 686-ton castle-destroyer.

Now, what about momentum? The good news is that as long as you know how momentum works with that spell (the sort of thing the DM would rule) you can make it hit the target either way.

If velocity is maintained regardless of mass, then you just aim it at the castle and smash it with its far-higher-than-it-should be momentum - essentially, the momentum grows by a factor of 33,000.

If, however, it's momentum that is maintained but not velocity, that means that as soon as the spell ends when your party drops concentration, the block will more or less come to a stop (technically its speed will drop to .00003 of its previous speed, which will look a whole lot like it just stopped.)

If this is the case, no worries. Instead, just aim above the castle (high up, if you can.) Then, as soon as it's right above the target, you drop concentration and this 20-ft cube of granite will plummet directly on top of the castle.

As long as you know ahead of time how that works (and a good artificer will experiment to understand the spell before attempting something like this,) you'll be prepared to use it correctly.

And now, any object that isn't made of adamantium is going to be utterly destroyed by your brick from the sky.

And the best part?

You can do this twice in a single day.

Wednesday, February 3, 2021

What is Next in Shadowlands?

 You might notice I've been a bit light on lore speculation posts. I think the reason for this is that Shadowlands has simultaneously given us a ton of story while also leaving us with far more questions than answers - even to the extent where it's not totally clear where to start.

The covenants mostly have a fairly obvious direction to go in, and I think that with the end of Castle Nathria, we've got hints at what might come next for the full expansion.

First off, let's talk timing.

Castle Nathria is the first raid of the expansion, which would seem to put in in the same category as Mogu'shan Vaults, Highmaul, The Emerald Nightmare, and Uldir. It's a full-sized raid, with ten boss encounters, but by earlier expansions' standards, it would still not be a "tier raid," officially (and indeed, there were no tier sets, though we also didn't get any of those in BFA, and we don't know quite what or when tier sets are going to make it into Shadowlands.)

Still, if we assume that the expansion follows the patterns established in the last couple, we can expect there will be another major raid to come in 9.1, and others in 9.2 and 9.3. We might also get a smaller raid to go along with the next big one, in the style of Trial of Valor or Crucible of Storms.

And frankly, that's more raids than I could easily predict. Essentially, I'm sure we'll get a raid in the Maw at some point - possibly in something like "Torghast Pinnacle" or the like. But while I think there has to be a Maw raid, the other possibilities are, I think, less guaranteed.

Still, let's talk Covenant stories. The campaigns reached their conclusions (if you were caught up on Renown, though it's pretty easy to catch up on Renown, thankfully) a couple weeks ago, resolving some stories while leaving others open.

Let's quickly touch on each of those:

SPOILERS AHEAD FOR LIVE CONTENT (WHICH I THINK IS ALL WE HAVE RIGHT NOW)

Tuesday, February 2, 2021

Sire Denathrius - LFR Tank Perspective

 The "Audience With Arrogance" wing of Castle Nathria is now open on LFR, meaning the whole raid is out for those of us with trouble getting out guilds started on stuff to see the conclusion of Shadowlands only current raid.

I've now tanked this on my Paladin and Death Knight.

This one-boss wing is just the final fight with Sire Denathrius, and given that fact, it's not shocking that there's a lot going on.

You can certainly brute-force you way through a lot in this fight, but there are a couple things that will make it a lot smoother if you understand them:

First off, there are three phases, with a transition period between phase 1 and 2.

Phase 1 begins with the Sire placing four stacks of a debuff on everyone in the raid. He'll periodically do a cone attack aimed at the tank that will remove one stack from anyone it hits and spawn an add for each person it hits. These adds should be burned down with AoE.

Now, I believe that you need at least one stack of this by the time the transition phase begins, so you'll want to have one tank taunt when the other one is down to one stack - though that might be just a thing for higher difficulties.

Over the course of this phase, a quarter of the room will periodically be covered in nasty stuff, so you need to run him around the room - you lose space to work in, but as long as you get him to 70% before you run out of room, you'll be ok.

At 70%, the transition begins. He'll toss everyone back to the edges of the room, and you'll all be slowed depending on how many stacks of the debuff you have. You're also silenced, so if you activate a speed boost right before this starts, it'll help a lot. You need to run to the boss and get out of the big donut-shaped AoE. Approaching him clears the debuff stacks, but if you don't reach him, you won't be protected from the massive fall damage that you'd take when you plummet down to the depths of the castle.

Now, phase two starts.

Tanks will need to juggle Denathrius and Remoria, his sword. Denathrius has a narrow cone attack that will damage and debuff the tank as well as anyone it hits - including adds. Meanwhile, Remoria has a stacking bleed debuff that will necessitate a tank-swap periodically. One key to tanking in this fight is that the boss (or the flying sword) will teleport to whoever has threat on them. Periodically, Denathrius will do a big AoE around him. However, if you're on one of the points of the cross-shaped arena, you can easily run through a soul-mirror to get to the other side of the room, getting out of the AoE (and Denathrius will blip over to you.)

Tanks can aim the cone attack at the adds on these points or to adds that are inaccessible from melee - dps should focus on taking down all the adds (I think).

Remoria will occasionally do something called Massacre, which creates many overlapping lines around the room that you'll need to dodge, as she'll then slash along those lines, hitting anyone in the path.

Once you get him to... I want to say 40% or so, Denathrius will take up Remoria and create nasty aoe around the soul mirrors, so you'll need to get to the center of the cross platform.

Taunt-swaps are pretty conventional here. You'll want to tank him near enough to an edge that people can get out of his big aoe circle, but not so close that anyone can be knocked off the platform. Massacre and the bleed will continue in this phase. The main thing is you have less room to work with and there's a sort of enrage timer enforced by the fact that he'll periodically cover a third of the space in nasty red anima goo, similar to the first phase. If all three thirds are covered, you're basically going to die (we had a 1% wipe thanks to this on my DK).

Looting Remoria off him, you can place the sword at the tower where the captured Naaru from Sanguine Depths is hanging out, and it turns out that Denathrius' soul is now trapped in his sword, which is then being "reformed" by Z'rali. If you are also caught up on the Torghast story quests, you'll immediately get another quest that has Bolvar get another vision into Torghast. Turning in the sword and talking to Bolvar both give you 1250 anima, so if you want to knock out your weekly anima-collection quests easily, you can save the latter for next week (though you'll have to wait for a cool and interesting cutscene.)