How is grabbing thunder comparable to an island sized, CoA/CoC, thunder imbued fist on the verge of destroying Onigashima?
Which is... lightning fast and a kind of pain that surpasses durability. But he couldn't even tag Kaido. Obviously this should be stronger and maybe harder to dodge because of the sheer size, but Kaido isn't on the verge of thinking he's in trouble. He was just mocking Luffy, that's not the state you really have the villain in before the KO