No... he's not a Sleeper OP. He's a champion no one really uses so people probably forgot what he does. But when you know what he does, and you fight against him, he's just all around shit.
The worlds worst hitbox for E.
A knock up that is hard to land because it has one big freaking tell and takes forever to come down not to mention how small the hitbox is for the knock up.
A passive that sounds nice on paper, but when it's triggered people just wait for you to get back up and kill you again because your passive is what makes you stronger.
You need to spend health for damage for some freaking reason.
Your early game is horrible, but your late game doesn't compensate.