After a concerted effort to get players in my guild attuned for Return to Karazhan, tonight we finally stepped inside.
The rewards of RtK are significantly higher than those of ordinary Mythic dungeons, and there's a good reason for this: Return to Karazhan is less of a dungeon than a 5-player raid.
While Mythics can be unforgiving (Cordana Felsong, one of the prerequisite bosses to gain entrance to RtK, is a good example,) RtK is the kind of place that you're going to have to progress through. Obviously, part of the reason for this is that there is no lower difficulty for the instance - much like the original, there's just one version, and you either beat the bosses or they beat you.
I will be very curious to see how things work out when there is a Heroic, queueable version of the dungeon, but for now, you're going to have to be careful on each trash pull and really strategize on every boss.
Opera Hall - Wikket
This week's Opera boss was Wikket, in which you fight Galindra and Elfyra along with the latter's flying Hozen. We managed to one-shot this (despite losing our hunter rather early on,) but I also suspect that this one is the easiest of the three Opera bosses.
The two bosses share a health pool and mostly cast spells at the tank. As a Paladin I could frequently use Avenger's Shield and thus was able to move the bosses around when needed.
Elfyra (the Troll) will periodically cast Defy Gravity on the ground, making a purple swirling vortex. You want to avoid stepping in these (for now.) Galindra will cast these arcane runes underneath you that you want to step away from.
Periodically, Elfyra will summon her flying Hozen. While these guys do have an aggro table, I don't believe they will do anything except throw "stuff" at random players, so as a tank you don't have to worry about them too much (still, tossing some damage their way isn't a bad idea.)
DPS will want to kill the flying monkeys, as more will keep coming over the course of the fight and you don't want to get overwhelmed.
The main event, as it were, is that Galindra will cast something called (I believe) Magical Magnificence, which does nearly 2 million damage to anyone on the ground when it goes off. At this point, you'll want to hop onto the vortexes created through Defy Gravity, lifting off the ground for a couple seconds and taking a much more modest (around 300k) damage instead.
Any DPS that can should try to multi-dot both witches, as it all contributes to the win.
After the Opera event, you'll be able to go in a few different directions.
We initially went for the Maiden of Virtue. This boss is very unforgiving, and after three attempts, we decided to explore a bit more.
The other two bosses (assuming it's only two) that are accessible at that point are Attumen the Huntsman and Moroes.
Unfortunately, we were running out of time, and we had accidentally left up some trash near Attumen when we pulled, causing a very swift wipe.
I'll make updates while we progress through the dungeon. Also, look out for my Trial of Valor raid finder impressions as soon as I've run it.