Phantom questions

I need to do more reading - or perhaps it's just a specific Google search. The Phantom (aka Ghost Who Walks aka Mr Walker) when required to take someone out of action for a while, punches them - leaving a skull imprint at the point of contact. This "looks like it was stamped in with a sledge hammer" and cannot be rubbed off - ever. So what is the secret of the Phantom's ring? Surely the Phantom, mere mortal despite his PR, can't hit someone that hard? Or is some special jungle "juju" at work here? To mix superhero taglines: to the computer cave ... Log-in!