Again, I don't see the problem Ultear coming back as long as they have a good reason behind it.
If the reason is crap, then I will totally agree on BS with Ultear coming back.
When it comes to death or "fall" of characters, I don't mind if they come back as long there is good reason/backstory behind it, and they give the revived character a "great comeback" and role that makes their revival worth it.
Examples is like Elaine, Matrona, and Hellbram from Nanatsu no Taizai, Minato from Naruto, Ayumi from Charlotte, Alibaba from Magi, Uni from Reborn, Sabo from One Piece, etc..
They all had meaningful deaths/falls, but were able to come back with no issues and make the story as appealing (maybe even more).
Compare to Dragonball's revive issues, this kind of "revive" is great as long they give nice explanation.