He-Man/ThunderCats all sides, He-Man defeats them all with help from Randor. Back in Skeletor's lair at Snake Mountain he explains to Mumm-Ra that he could never wield the Power of Grayskull without it consuming him. But by mixing Mumm-Ra's ashes to a potion it will link Mumm-Ra's ever living power to him allowing him to use the Power Sword. Despite Mumm-Ra's protests Skeletor drinks the potion and summons the Power of Grayskull to him adding He-Man's strength to his own. He-Man suddenly is transformed back into Prince Adam in front of Randor who is horrified as his son collapses in his
He-Man/ThunderCats friends and He-Man and Lion-O rush into the Castle. He-Man guides Lion-O through the maze of Castle Grayskull saying it is a nexus of worlds and reality through space and time and they must find the Sorceress before it's too late. They arrive at a shattered door that shocks He-Man as he says no intruder has ever gotten so far into the Castle. Both heroes charge forward and find the newly formed Mummator imprisoning the Sorceress and holding an orb that is the heart of the Castle, the key to all the power that Greyskull possess. Mummator says that he