Oh, I think I misunderstood what you were saying. I meant Bounce happens at the start of the action, then attacks at the end of the action. Sorry about that! That's where the "two-turn" thing rang a bell for me for some odd, mysterious reason. If you said "two-action", I think that would've made better sense. But yeah, Magikarp bounces through the air and falls onto the Pokemon at the end of one action.
There really aren't many moves that take two actions or more. There's Bide and... I think that's it.
Anyway, sorry for that!