We have pretty much every de-buff(bleed, poison, blind, fear, charm, slow, taunt, ect) besides confuse. I'm not sure how such a mechanic would work in league, but I just wanted to throw that out there as a possible ability for a future champion.
**Inverted Controls?--** If you click to move forward, you move back. You try to go left, you go right.
**Ability Spam?--** Your abilities randomly go off, including summoner spells, burning mana and/or energy.
**Friendly Fire/Enemy Healing?--** You attack your allies. If the champion has a heal or shield, it will be cast on nearby enemies. You have no control over abilities or attacks.
Not sure if this has been brought up before. I think it would be an interesting mechanic to have in-game, but you guys are welcomed to express your opinions.