Soraka - Way to safe for her power. Makes no tradeoff for most of her abilities.
Tyndamere - Also way too safe while also permanently splitpushing, and since you can't kill him 1v1, because of his ult, it just seems useless.
Master Yi - Still a bit on the strong side, while not dealing too much damage, he can still dodge CRUCIAL abilities with his Q
Volibear - Has waaay too much damage for his overall tankyness
Garen - Too easy to play, and too forgiving. I understand this is a newbie champ made to teach players how the game works, but when he starts dealing 1.5k TRUE damage with his ultimate and can silence you while getting movespeed. It's just a TOO forgiving conscept.
Feel free to add to my list and or give me reasons why these champs are not unhealthy for the game