(idk if this counts as dark or not but I feel like the Lich would do this kind of thing) you are just a normal human whose lived amongst the other beings here in the land of Ooo though with you husband who was human too though this time you had become pregnant with his baby and sadly your husband was killed by a being you never met before so upset did you keep the baby and decided you were going to raise them in honor of your husband though what you didn't know that day when your husband died the one who did it decided to take over your unborn baby for himself in a sense possessed it as the Lich got very comfortable the whole pregnancy without being detected whatsoever that is until Princeton Bubblegum suspected something was off so she had you come to the Candy Kingdom and she used an ultrasound device as she had Finn and Jake wait outside as she came to a conclusion with your baby and her suspicion were correct about the Lich being your baby after he took it over so weirded out and concerned did Princess Bubblegum step out of the room to tell Finn and Jake what she found and all you heard was a loud 'WHAT!?' From Finn as Jake spoke though it was too muffled for you to hear as you lay back on the bed for a bit since your practically eight months pregnant though it seems on the other side of the door Princess Bubblegum is going to keep you here in the Candy Kingdom until you give birth so she can decide on what to do because what the Lich did was so cruel it might mess up your mental health more after your husband's death and the Lich used it to his advantage just to come back and do his usual shenanigans as himself though more so a human but Princess Bubblegum caught on to his plan and she plans to thwart it to save you mentally and physically from what he's done but she's not gonna tell you that the Lich is currently your child since she didn't want to send you over the edge anymore...