Warning: Contains SPOILERS for Masters of the Universe: Revelation season 1.
Masters of the Universe: Revelation culminates in Skeletor transforming into his final form, dubbed "Skelegod" by Kevin Smith. Skeletor has always been the greatest threat to the peace of Eternia, the self-styled Lord of Destruction who seeks to gain the power of Grayskull for himself.
Masters of the Universe: Revelation season 1, episode 1 plays out like an installment of the original animated series, with Skeletor using illusions to infiltrate Castle Grayskull and break open the Orb of Power containing Eternia's magic. Both He-Man and Skeletor were seemingly killed in the flare of mystical power as the Orb was destroyed, but it turned out Skeletor had faked his death. The Lord of Destruction returned in episode 5, killing He-Man once again and finally claiming the Sword of Power for himself. Skeletor's plan has been criticized as being rather out of character, in that it actually required a degree of foresight he has never shown before - but it proved remarkably successful.
Skeletor uttered the famous words of power, transforming himself into an apocalyptic final form - referred to by tie-in merchandise as Skelegod. This towering new incarnation of Skeletor is shown looming over Castle Grayskull, symbolizing the fact he has absorbed all the magical power in the entire universe. He is surrounded by ethereal energy, which has his trademark green color.
Skeletor has always been a force to be reckoned with, possessing enough raw magical power in and of himself to take on almost any of the Masters of the Universe - with the sole exception of He-Man. Masters of the Universe: Revelation season 1's ending reinforces the sense of his sheer raw power, revealing he was even able to transport his spirit into Evil-Lyn's orb in order to escape death at a critical moment. But now, in addition to his own abilities, Skeletor possesses all the magic of Grayskull itself. He is literally the most powerful being in the universe.
There is only one way to defeat Skeletor. Somehow, somebody needs to steal the Sword of Power from his grasp and claim the magic of Grayskull for themselves. Unfortunately, this all-powerful version of Skeletor - this Skelegod - is unlikely to give up the Sword of Power easily, and Prince Adam has been killed once again. Masters of the Universe: Revelation ends on a bleak note, and it remains to be seen how Teela and Eternia's remaining heroes can possibly triumph against him in Masters of the Universe: Revelation season 2.