[quote=@Vongola_Hasayo]
[@Archmage MC] arrancar have high speed regeneration as well. Some don't because they give it up for greater power
[/quote]

To be fair the lore of Bleach is so wishy washy past the Soul Society arc that you can pretty much just put it all up to interpretation. a 100 chapter fight vs the main baddie with a Deus Ex Machina pulled out of nowhere to finish him was incredibly stupid.

So... What exactly are the problems with a regen character? That you can't kill them? Is that all?