User blog comment:Lykrast/Aur, gold's master/@comment-3974211-20121201175915/@comment-3974211-20121201181825

They used to have mana burn. Kassadin's W; Wit's End, etc. But players didn't notice that it was happening until it entirely shut down the enemy; in which case, it was really frustrating. What's the point in a mechanic you don't notice unless it's "really f*cking annoying"? ;)

But yeah, I've got on one of my supports called "Crippling Penance" that causes an enemy to take damage whenever they attack. Statistically, it's no different to any damage over time; actually, it can be much worse (for the user) since it has the potential to do nothing. But, apparently, giving them enemy the choice and punishing them for the "correct" choice is a bad mechanic. :(