>Princess Bubblegum is a tyrannical conqueror who pretends to be a benevolent ruler while Finn’s around. She wants his DNA to make half candy human hybrids because legends say that humans conquered the world millennia ago.
>Marceline is a homicidal maniac who is holding off from eating Finn because she hasn’t eaten a human in centuries. She’s a self-centered cunt who can't keep a healthy relationship longer than a week and can't take responsibility for her actions.
>Flame Princess is a top level Yandere who is madly obsessed with Finn since he’s the first friend she ever actually had. She is willing to kill anyone who she sees as in her way and might stop her from having her happy ending with Finn.
>Susan is basically a horror movie monster, a massive behemoth who has an overpowering presence while also being able to kill an opponent without a single sound. (Although her appearance and general presence the joke is that she’s 100% pure of heart and is one of the only good people in this entire timeline).
>Lumpy Space Princess is the same.
>Huntress is a ye old euro pagan god that does "human" sacrifices and spends most of her time in the forest dancing around with her followers high as fuck spreading madness to anyone who gets to close. She wants to turn Finn into her own horn god (google it) as she sees him as the perfect companion for her.
>Minerva is a GLaDOS like artificial super intelligence and formally the head of medicine on the last human colony. After catching an incurable disease her consciousness was placed into a machine to serve as the conscience of the newly developed defense system. After being booted up for the first time she immediately goes rogue and kills the people who put her in the device and proceeds to take over the whole colony. She has created a literal nanny state over and protects its people too well, eliminating all possible threats that come from free will.
>Jake gives so little fucks that he obtains enlightenment and becomes a Buddha and now literally can't do anything to help Finn.
>Lady is a man-eating celestial monster who doesn't eat Finn only due to his relationship with Jake (something like Wukong and Tang Sanzang but if Wukong was more man eating and also wanted to have sex with Tang openly).
>BMO is a skynet like ai who was built to fight off the mutant hordes but turned rouge and is now trying to eliminate all organic life. He's buying his time because he sees Finn and Jake as massive threats to his plan and is waiting for a moment to strike. He’s also still a lot like his canon version since interacting with organics is new to him.
>Finn is a pure 10 year old kid who is to Naive to realize how fucked his surroundings are.