In that case, this should be even easier than the fight against Gaara since Gaara was casually stronger than Kaneki's Feat and his sand could somewhat keep up with someone who could literally Blitz him, so Kaneki isn't anything new compared to Gaara or really most of the Stuff the Ashen One has dealt with at this point. That Class M is gonna be really annoying if the Ashen One tries to use the Dark Hand, but all their other Hax should still be Viable, especially stuff like Invisibility, Freezing, Homing Attacks, Fire, Dura Neg against Shields (not sure if Kaneki has any shields but still), Acid, Poison, Shockwaves, Healing, Summons, etc.