I am so late, but Kaine for the majority. Kaine was able to fend off the guild by himself and a room full of The Hand ninjas completely surrounding him , and was able to shake off their attacks in seconds. He’s also been able to defeat Otto who is much faster than him, and even then he was holding back significantly. Also I don’t know if this puts any weight on his speed but Kaine was able to fight off a guild member and turned around catching an arrow in between his palms. All the other points were already pointed out. But basically: He’s been trained by the guild, he’s able to multitask and strategize quickly, stronger, brutal, stingers, and acidic touch. His durability is also important because if he wanted to get close he would let her attack him, taking hits to be able to catch her.