Quote Originally Posted by Razade View Post
Cero of any sort aren't shown warping space time. They're just condescend spirit energy.
You are correct we never see it do anything particularly interesting, but on-lookers specifically state it warps space. How they made that determination is anyone's guess.

"Just condensed spirit energy" means nothing. It's like saying a Naruto attack is "just condensed chakra". Or that Might Guy's attacks are "just raw physical force" - a particularly apt comparison because Might Guy does bend space, according to Madara, when he opens the 8th Gate.

Quote Originally Posted by Razade
Grimmjow also can't use Garganta on the same plane as far as we know. Only traveling between Hueco Mundo and the mortal realm and Soul Society.
The actual process goes Earth <---> Void <---> Hueco Mundo, with Void <---> Dangai and Void <---> Soul Society also shown. Furthermore, Hollows aren't limited to single location at any end. We've seen Grimmjow leave and arrive at multiple places. So even if he has to take a detour through Hueco Mundo to get to a different place on Earth, the ultimate effect is similar to space-time-ninjutsu.