Kaneki's main thing is his AD and RE. The more damage Kaneki takes in a fight, the stronger he gets, during the end of part 2, we see Kaneki get his ass beat by Furuta and then one tap and blitz him a panel later. We also see this with the Dragon Tentacles, who basically turn Kaneki into mush, and then immediality after, he blitzes and one shots 3 at the same time. More damage = more strength.
He also has very good LS with his Kagune, and he spams the absolute **** outta it as well. From below, blindspots - all at the same time, while attacking you himself. He also has High - Mid regen, it pairs very well with his RE and AD hax.
RE + AD + Regen + Skill + LS is his main thing.