It seems that an old enemy of Xavier has returned in the form of the Shadow King. He attempts to take over the Professor's body in order to rule the world by playing mind tricks. The Professor unfortunately wasn't strong enough to defeat the Shadow King himself, and was forced to yield his body to him. The Shadow King made his attack while the X-Men watch helpless as the Shadow King attacks in the body of their beloved professor. Jean searches for Xavier by sending herself in the Astral plane, rescues Xavier, and locks the Shadow King up once again.
Boring episode, a bit confusing at times too. If it weren't for Xavier's commentating, I guaranteed you would be completely lost in this episode. All this psychological stuff felt like it was thrown together randomly, but instead it was just confusing. It's also one of those episodes that had a rushed ending--but I feel the same way for almost all X-Men episodes. The content itself was pretty badly executed, and the corny battle at the end was the only redeeming factor in this episode, even though it is just a replica of the various famous battles in Star Wars.