As far as I understand them, they don't hex but they rip the engines apart by hand. So the stunt to disassemble things, maybe inhuman strength (or more), because ripping apart an engine with your bare hands is not really easy. Maybe instead of hexing you can give it a supernatural sense, that helps him find a weak spot in an engine (as in he can use it to declare a weak spot aspect and then tag it for more effect when disassembling). You already mentioned stealth, he should definitely have a decent score there to sneak on a plane. Maybe something like Spider Walk, restricted to moving vehicles, but it also increases stealth. And he should be able to survive a crashing plane, so he should either be able to cross over into the nevernever from there, or he has some sort of wing power to be able to glide down, if he is on a plane. I think crossing over into the nevernever would fit better, and he should be able to do this without any power, as long as he is doing it from a vehicle he just trashed.
Smell the weak spot [-1]
You have the ability to smell the weak spot in any vehicle. You can declare an aspect that describes a weak spot in the mechanics of the vehicle you are on.
Gremlins Grip [-1]
When climbing on a moving vehicle, you suffer no penalties for moving around due to the surface or speed of the vehicle. Your Stealth is increased by +1 when trying to hide in or on a vehicle.
Maybe Claws, so he can do even more damage.