Skeletor at his best had the full Power of Grayskull embedded in his body, and unfettered access to the Eyes of Grayskull, which control time and space.
Baaically, he's an abstract being. He destroys Earth or wherever in the past, before he can become Ghost Rider.
__________________ What CDTM believes;
Never let anyone else define you. Don't be a jerk just to be a jerk, but if you are expressing your true inner feelings and beliefs, or at least trying to express that inner child, and everyone gets pissed off about it, never NEVER apologize for it. Let them think what they want, let them define you in their narrow little minds while they suppress every last piece of them just to keep a friend that never liked them for themselves in the first place.
He did that in comics? Pretty bad ass. Though, to be fair Mephisto can do all this too. Also Zarathos existed before the earth. This is Zarathos in the battle.
__________________ Too much work trying to figure how to size a Sig right to have one.