Kokushibo vs Aizen

Kokushibo is a powerful swordsman with a lot of eyes so it can be hard to get anything past him. Aizen is a master of manipulation though so that’s a challenge he would certainly welcome. While breathing arts may possibly help to reduce the strength of an illusion, Aizen can always just fall back on his brute strength. When he is fighting all out in his hybrid form Kokushibo will be unable to keep up with this guy. Aizen’s got too many tricks up his sleeve. Aizen wins.

Kokushibo vs Priscilla (Claymore)

Kokushibo is a powerful demon with so much raw power that pretty much all of the other characters fear him. One on one it’s quite possible that none of the Demon Slayers would be able to match him. He just continues to grow more powerful with each passing moment. Priscilla also has solid sword techniques and even a powered up mode of her own but physically she wouldn’t be able to keep up with the sheer speed or technique of Kokushibo. She would not be able to endure these attacks. Kokushibo wins.