You can sometimes use Twitch's E (Contaminate) without it doing anything.

As a Twitch main, this happens fairly often and is quite annoying. I'm not sure what causes this bug, but it seems to happen when you use your E and the enemy is just out of range from the indicator (for those of you who don't play Twitch, whenever enemies have Deadly Venom applied, a circle appears around Twitch that shows how close he has to be for Contaminate to effect them). The animation goes off, Twitch sort of jumps up and enemies have green poison come from them, but the spell does no damage. I wouldn't have a problem with this, since I believe the enemies are technically out of range, but doing this puts his Contaminate on its cooldown and uses mana as if you actually used the spell. This can lead to instances where you Contaminate a 6 stack target that is just barely out of range, then they come back and kill you because your nuke spell did nothing and its now on CD so you can't actually use it. I just want this bug fixed cause it's annoying having your enemy just barely escape because your Contaminte did no damage yet it is put on CD and drains your mana.