Tasha's, Class by Class - Cleric

 Ah, yes, officially and intentionally the most powerful class in D&D, Clerics are the most iconic healers in the game, but they also come with a lot of other tools to make them quite powerful in other aspects. Let's get into class features:

New Spells:

Clerics already have a rather unique and powerful set of spells, and I'll be honest, some of the ones added here I really assumed they already had. But in addition to a couple from Tasha's, the PHB spells they now also get are: Aura of Vitality, Aura of Life, Aura of Purity, Sunbeam, Sunburst, and Power Word Heal.

Harness Divine Power (2nd level):

You can expend a use of your Channel Divinity to fuel your spells. As a bonus action, you touch your holy symbol, utter a prayer, and regain one expended spell slot, the level of which can be no higher than half your PB. You can use this once per long rest, or twice at level 6 or higher or thrice at level 18 or higher.

Cantrip Versatility (4th level):

Any time you get an Ability Score Improvement, you can swap out a cleric cantrip you know for a different cleric cantrip.

Blessed Strikes (8th level, replaces Divine Strike or Potent Spellcasting from your subclass):

When a creature takes damage form one of your cantrips or weapon attacks, you can also deal 1d8 radiant damage to that creature. Once you use this feature, you can't again until the start of your next turn.

    My sense is that this is actually generally worse than the features it replaces, though it does mean you can use it as an opportunity attack, and radiant damage does sometimes disrupt particular foes like vampires. Still, it doesn't scale up like Divine Strike and Potent Spellcasting, which will be a +5 after you've gotten your Wisdom capped, will be on average a little better than a d8.

Subclasses:

Order Domain:

This is another reprint from GGtR, which seemed primarily built for the Azorius Senate (though it also works a bit for the Orzhov Syndicate.) Generally, there's a teamwork and enchantment theme to this subclass, allowing you to really enforce your will upon your foes and get your allies to hit harder and more often.

I don't think this one took off quite like Circle of Spores, but it's a solid subclass.

Peace Domain:

Ultimately, this domain is really focused on teamwork and synergy, creating bonds between allies that protects them. You can basically turn your party into a super-team that can constantly help one another out.

I imagine this could prove pretty powerful in a group that uses all these features, spreading the damage out and assisting one another on various rolls.

Twilight Domain:

The theme here is all about lighting - in addition to getting a freaking 300-ft darkvision, you can also create a kind of sanctuary of dim light around you that bolsters allies and cures charms and fear effects. You can even fly while in dim light or darkness.

    Personally, I think Twilight wins in terms of flavor and fun factor for its abilities. Both Peace and Order domains seem good from a mechanical standpoint, but require some heavy lifting on the part of the player to make the idea of their domain interesting.

    I think Clerics have a bit of the Wizard issue - the main thing that's powerful about the class is its spell list, and while that's certainly nothing to be scoffed at, it does mean that the actual class and subclass features are generally less flashy than, say, that of a Paladin or a Rogue.