Caitlyn - strong, but stoppable, her damage is preventable. Bitch in the laning phase though.
Fiora - Her burst may be a bit rng sometimes with those vital procs, but all seems fine with her.
Fizz - Needs to land his ultimate to do some very sick damage. Tidal/Trickster is no longer overpowered with the amount of mobility available in league.
Malzahar - Low skill, low counterplay champion. Hard countered by qss. Gets outcarried by most mids.
Twitch - squishy, without any escapes, without any defensives, is a full offensive adc which gets rewarded with a godly late game if he gets to there. Nothing unhealthy here.
Yasuo - Can't say anything that hasn't been said before. Extremely rewarding when played well. However the amount of times he can fuck up and comeback into the game is pretty insane. However he's still a high skill cap champion and is mostly dependant on his user.