Originally Posted by Silver/
I mean, it's essentially infinite death ward. I still don't know what Larian was doing here, they just wanted an Aasimar that it also "the daughter of Selune" for flavour, while having Deva like wings.

https://roll20.net/compendium/dnd5e/Deva#content

https://bg3.wiki/wiki/Aylin

She doesn't have the Deva statblock, or at least not that one. She lacks passives like magic resistance. She has oath of Vengeance spells and slightly higher AC. She lacks the innate additional radiant damage seen in Devas. She has fewer hit points. Exceptionally strong Aasimar maybe, but weaker than the average Deva is supposed to be. She's just an unholy (or perhaps exceptionally holy) amalgamation of traits.

The lack of advantage on rolls against magical effects sucks massively in the Act 2 fight, since if you make the mistake of hard focusing Ketheric, the mind flayer can earn itself a powerful puppet.

To be fair, Larian didn't copy the stats of most 5E creatures perfectly, either to account for difficulty balance and the game mechanics or just because. Luckily, we have Larian's take on a Deva's stats from the Deva that you can summon in the game itself, which would be the more accurate comparison: https://bg3.wiki/wiki/Deva

Still slightly different, but much more similar.