How does the balance of the UA Twilight Domain compare to the official Twilight Domain from Tasha's Cauldron?

Question

I have been playing a Cleric whose sub-class is the Twilight Domain from Tasha's Cauldron of Everything. I have been using the official Tasha's version of the domain, but there is an Unearthed Arcana version of the domain that was published before the Tasha's version. The two versions of the subclass are fairly similar in theme, and presumably WotC made changes in the Tasha's version that improved balance issues with the UA version.

I'm curious about the differences between the UA and the Tasha's version of the domain. I've put a bunch of context for this interest at the bottom of this question (but I don't consider it critical to giving a good answer).

What I'm wondering here is whether using this alternate subclass is likely to cause balance issues that we aren't seeing yet. Specifically:

• Are there any official resources that discuss the reasons for the changes between the UA version and Tasha's version of the Twilight Domain?
• Are there substantially unbalanced abilities in the UA version of the Twilight Domain that we should be aware of? (In particular, I suspect that the level 17 ability might be worth rethinking.)
• Are there other (good subjective) experiences with rebalancing the Twilight Domain at your table and how to make it more fun/strategic for the whole party?

Extra Context

(Not necessary for answering the question—just an explanation of the motivation here.)

In the campaign we are currently playing, it is becoming clear that my character is quite overpowered with respect to the rest of the group. (I'm not asserting here that the Twilight domain is generally overpowered—though that seems to be a popular assumption in many forums—just that my character is more powerful than anyone else's, in part due to other choices during character generation). In chatting with my GM about this, we came to the agreement that the UA Twilight Domain appears to be less powerful than the Tasha's version and have adopted most of its features in place of the Tasha's features in order to make the game more fun for everyone (we are currently level 7). Simultaneously, the UA version of the domain fits better with certain ways that I've interpreted the Twilight Domain for my character, so the change feels like a win-win.

So far, this change appears to have worked for our party—since the change, we have been substantially more challenged by encounters tuned for our CR, and my character's ability to influence combat feels much more aligned with the rest of the party. Previously, the twilight sanctuary ability (when I managed it wisely) tended to make our harder fights pretty trivial; now it just helps out in these fights. (FWIW I suspect we accidentally built a party that could exploit this ability well.)

Answer 1

The published version is stupidly powerful.

I recently played through a good portion of Icewind Dale: Rime of the Frostmaiden as a Goliath Twilight Cleric. Let me tell you this: how this subclass ended up being published the way it was is beyond my comprehension.

That said, there is one feature of the subclass that stands out as the chief offender of imbalance, and the UA version actually fixes it quite nicely: Twilight Sanctuary. But we'll get there. Let's examine some of the other features.

Eyes of Night

• Tasha's: 300 foot darkvision, can give it to n=WIS creatures for an hour 1/long rest, or expend a spell slot

• UA: Unlimited darkvision, can give it to any number of creatures for 10 minutes, can extend n=WIS times per long rest.

Despite the UA version being unlimited darkvision range, I'm going to say the published version is better. Being able to give it to the party for an hour is way better than 10 minutes, and not once did 300 feet make a difference. Everything I ever tried to look at was within the range of my darkvision. This feature is good, but not broken, and I think either version is appropriate for play.

Vigilant Blessing

Equivalent to always having advantage on initiative rolls. Not a big deal.

Steps of Night

• Tasha's: Fly speed for 1 minute, proficiency bonus times per long rest.
• UA: Fly speed till end of next turn for cost of bonus action.

The UA version of this is actually pretty broken as written, as long as you are in dim light or darkness, you can have a flying speed for as long as you want, since there is no limitation on how many times you can use the feature. The Tasha's version seemed pretty well balanced. I didn't use it all the time, but it did make for a good creative problem solving tool in a party where no one else had any form of flight.

Divine Strike

Pretty sure the psychic damage on the UA version is just a mistake. Otherwise the features are the same, and are just fine balance wise.

Twilight/Midnight Shroud

I haven't play tested these features, but the UA version seems way more fun than the Tasha's version. The Tasha's version is just a buff to an already overpowered feature. The UA version makes for some fun tactics.

Twilight Sanctuary

This is the feature that really matters here. Here's the short version: the published version of Twilight Sanctuary is too reliable and too powerful. It creates a 1d6+level hit points buffer for every ally, every round, for basically no cost. It doesn't even require concentration. It scales with cleric level, so it gets better as you level up. In contrast, the UA version is a flat 1d8 per use, which is (on average) equivalent to the published version only at 1st level (1d6+1). In my estimation, this is a good place for the feature to be. This way, it is similar to being able to cast aid for free every turn, which is good, but not broken, because aid by itself is trash.

Conclusion: Twilight Sanctuary is really the only squeaky wheel.

In my estimation, there isn't much difference between the UA and published versions, with the exception of Twilight Sanctuary. You might could try using the Tasha's version but requiring concentration, but that just limits what the cleric can do while it's up. Nerfing Twlight Sanctuary's healing ability is, in my estimation, the only thing that needs to be done.