Finn is needing a new sword, so he enlists the help of Peppermint Butler, who forges a weapon, the Night Blade, and then summons Hunson Abadeer (voiced by Martin Olson) to infuse it with "Nightosphere magic". Released unto Ooo, Abadeer initially tries to harvest souls, but Peppermint Butler binds him with a spell, rendering his powerless. Abadeer then decides to accompany Finn and Jake to the house of his daughter, Marceline the Vampire Queen (voiced by Olivia Olson).