Body Snatch

You cause the next person to kill you to become the next host of your soul. For the duration, if a creature would cause you to drop to 0 hit points, it must make a Charisma saving throw against 8 + twice your spellcasting modifier + your proficiency bonus. On a successful save, the creature takes 12d10 psychic damage as your souls fight for dominance, and theirs wins but not without cost. On a failed save, you possess the creature and their soul wanders around in the Astral Plane. 

You gain all the physical scores of the creature (Strength, Dexterity, and Constitution), and gain the mental scores of the creature (Intelligence, Wisdom, and Charisma) if theirs is higher but keep yours if yours is higher. You learn all spells they know, regardless of whether or not your class can learn it and can cast it as if your class can learn it. If the creature has class levels, you can roll 1d10. You gain features from their class levels of up to the number rolled, but don’t gain any hit points from gaining levels in those classes, don’t gain spells from gaining levels in the class, and do not gain any spell slots from levels in those classes. If that class allows swapping out their spell list on any rest, you are unable to do so. Features such as extra attack don’t stack, and resistances/immunities don’t stack. You are not considered a member of the stolen class levels, being still considered a member of your own class(es) (so if you steal wizard levels, you can’t suddenly use items only wizards can use). And you don’t gain levels if they are the same class as you (so if you are a wizard, you don’t gain wizard levels from the creature).