Riot, you need to looks into this champion's ability. I won't reveal his name, nor qq about his entire self, just this specfic ability.
First thing first. Why should this skill shot BE able to hit a champion, if they just GOT behind a minion, that just make this skill shot overpowered overall. The fact it can burst for % of your health is plain ridiculous for someone that can be built tank even tho he was intended to be built as dps. The fact it has low cooldown makes it a nice harassment tool, but the % of healths is just too much for A harassment ability, which makes it overpowered for some NON-tank which weren't intended to be a tank such as Garen, other Mundo, Mordekaiser, Xin Zhao. I don't mind if it's meant to be a counter against a health stacking tank, but imo it's bit too much for squishy champion that use health for purpose of surviving early game.
What I want Riot to do about this is to reduce the health % dmg early game, and increases the scale % per level up skill to the same max % as he would previously have at skill level 5 or bit higher. This skill is what make the champion unique, but it's just overpowered for some champions early game, and should be at least balanced for THOSE champions. Tanks probably wouldn't be affected by this change that much.
Now, end qq of this skill shot, you may go where you pleases.