Why does singed's poison trail use mana?

{quoted}

with that logic nothing should cost mana i dont see how reversing time can be powered by mana nor a ball of dark energy that locks enemies in place for a while nor dashing through someone nor spinning an axe in your hand

really does make sense when you think about it

[{quoted}](name=Ozag the Mighty,realm=NA,application-id=3ErqAdtq,discussion-id=9kxdjsIZ,comment-id=0001,timestamp=2016-03-26T17:42:06.436+0000)

Because his poison trail is his damage...imagine if it cost 200 mana at all ranks but never counted down his mana...he would be just like Swain in URF...hit R and just trot around the map...it needs to eat his mana.

But by end game it won't matter cause he won't run outta mana

he should use like gas or something instead of his mana bar