Sticks and Stones [Mastery I | WIP]

The Return [Minor]
There was a Cynical Man [Major]
Ai Spy [Minor]
Hokey Pokey [Minor]

This is a skill that is second nature to Cayo. Even though he's only a base hollow he's able to put effort in to regenerating his body in ways that most others around his stage of evolution wouldn't begin to think of. In the face of acids he's able to replicate skin and soft tissues to replace those that he knows he's going to lose. His body mimics that response when faced with an invasion of insects from Zero, knowing that letting them in is going to be his downfall. There isn't much, I'll admit, in Ai Spy aside from the mention that he eats his own limbs for sustenance knowing that they'll regrow without fail.  I think you'll find the best material for the mastery in There was a Cynical Man. He closes superficial wounds without effort and also uses the regeneration to try and push out shards of his mirrors. Although he does get seriously injured in the linked post, Cayo continues to heal his body. Admittedly it takes a large amount of concentration but for him not to have lost consciousness or focus is something to give him credit for, I think. In the end of the thread, Cayo proves that he's the master of his body. When Levi's serum makes his body balloon and inflate with new, cancerous tissues Cayo takes control of his body and forces it back into a state of homeostasis. He willingly lets the bits of himself that aren't right decay until they fall away from the healthy bits of flesh and regrows them. It's a lot of work and it's tiring, but he does it. All while being held down by Levi. 

This is a skill I do intend to GM, aside from that I don't think there's really anything else I really need you guys to know.