Through his Quirk, Chisaki is able to disassemble and then reassemble anything he makes physical contact with.
With it, Chisaki is capable of instantly killing people or destroying body parts, ripping body parts away and fusing them to foreign objects, curing all of a person's chronic ailments, and likely much more. While he is very capable of using his Quirk to kill, he is also capable of using it to 'revive' people as well, as he has done with Rappa multiple times.
It is a Quirk well suited for both destroying and healing. Additionally, it is also one that is good at covering Chisaki's escape tracks - His operating base has multiple corridors with dead ends, which he can use his Quirk on to disassemble and then reassemble once he has passed through.