I keep thinking about how sad and unfair Ice King/Simon's relationship with Fionna and Cake was in the main Adventure Time series. We all made fun of him for writing gender bent fanfiction of Finn and Jake. Characters cringed at how obsessive Ice King got about his fantasies, the lengths he went to so they could be real. He believed so fiercely in those ideas that he acted out in ways that were extreme even for him.

Typical Adventure Time to take a gag and make it into something serious.

Because Fionna and Cake WERE real. Prismo created them and their world and then dropped it into Ice King's head. Yes, he had permission but did IK know the reason? The risks? What even was happening? Or did Prismo take advantage of the fact that Simon was a prisoner in his own mind with little agency to force more confusion into his scattered and incoherent brain. How much of his actions was the result of a godlike being knowing that Ice King's resultant behavior would be written off and dismissed.

In addition to the loss of sanity and identity Simon had to deal with over his years as Ice King, he also had the burden on an entire universe of living people living in his head adding to his delusions. How devastating that must have been for someone who could barely tell what was real on a good day.