Cynan Machae
Smash Journeyman
No, Kirby can activate it midair, and stay in the air for his FS, so he actually has a pretty good point. There is an exemple in the 5 min gameplay video from Nintendo. Or it was in the Tokyo-Kyoto WiFi Matches? Anyway, one of those.Doesn't Kirby get grounded when he uses his FS? If so, your point is moot.
Marth definitely has one of the best Final Smashes, but with worse consequences should it fail. That doesn't mean it's a fair trade off though.
And is there a video of Marth killing himself with his Final Smash or is this only speculation on how it works?