This is GenieSimon

In this AU Simon actually decided to get on the bus with Betty, which lead him to come across different artifacts than in canon.

One such artifact was an empty genie lamp which sucked Simon in to turn him into its new genie when he rubbed it as a joke.

Once she got over the shock, Betty rubbed the lamp and became Simon's first master, trying to free him with her 3 wishes, but no way she tried to formulate it worked.

Once Betty's wished were wasted, Simon got stuck in the lamp and Betty held onto it, trying to find a way to get Simon out until she inevitably lost it during the mushroom war.

Little Marcy became Simon's second Master when she found the lamp in the rubble while looking for food and water.

Simon, seeing the situation the world and this lone little girl were in got Marcy to wish for him to take care of her for as long as she needed him. Her second wish was to change the lamp into something more huggable and despite his warning, she tried to use her third wish to free him, wasting it.

Thanks to her first wish, Simon was still able to leave the "lamp" though until she got old enough to take care of herself, then he was once again stuck inside the now plush-toy lamp.

Man, Iimagine their reunion must be very moving

PS. I love your art and your AUs are just amazing! ❤️

Thank you! ^^

I haven't planned out exactly how GenieSimon would reunite with Marceline yet, though most likely she's already friends with Finn and Jake by the time they discover GenieSimon so they would reunite through them.

Finn and Jake basically just kinda picked up his "lamp" (Hambo) along with some treasure and tossed it in their treasure pile, probably not really paying any mind to it, not even enough to wonder whether it's a regular plushtoy or something cursed or whatever, they definitely didn't know that it was something Marceline had been searching for for years at that point.

It's BMO who eventually discovers GenieSimon and allows him to come out again when he finds the plushie between all the gold and gives it a hug, becoming GenieSimon's next master (since the lamp was changed into a plushtoy the requirement to rub it has been replaced with giving the plush a squeeze).