Fiora is busted
Nothing tilts me more than seeing a Fiora at 1/5th of her health heal all the way back to full because she completed a stupid little mini-game. Not only that, but if she manages to pull it off in a teamfight (which isn't hard with her mobility) her whole team around her heals back up too.
It's such a huge heal that even with grievous wounds, it's more than enough to result in a teamfight win.