"Messy how? Like... Explosions and teleporting and flying and unicorns and stuff?" You know, all the usual things that happen when his magic doesn't cooperate. He's pretty used to those kinda of mistakes, since they've followed him his whole life. It's the problem with understanding how to use magic like he does; he knows all about how to manipulate it to get what he wants, but doesn't know about what he's actually doing to avoid pulling the wrong thing out of place, and, well... That can definitely be a bad thing, even if the power it comes with is good.