This is how I think it works.
The user relegates their soul into their fist, and punches the Earth. The soul is a gift to the devil, and the devil grants them invincibility for the few fucking seconds it works. And then when you release it there's that EMP blast of faggotry and idiocy that disables and vehicle or shields near it with it's magnitude of shitfuck.
But that's only the first time. Seeing that they have already sacrificed their soul, all other times use the tears of children, puppies, and dolphins. At the same time.