You touch an undead creature at least one size category larger than you and merge into its body for the duration. An unwilling creature that succeeds on a Wisdom saving throw is unaffected and can't be targeted again by you for 24 hours. While merged, you assume the game statistics of the target, including its Hit Dice and current hit points, but use your own class features and Intelligence, Wisdom, and Charisma scores. You also retain all of your skill and saving throw proficiencies, in addition to gaining those of the target. You can't use any of the legendary actions or lair actions of the target.

The spell ends if you drop to 0 hit points while merged. When the spell ends, you return to the number of hit points you had before you merged, and you choose to either exit the target and appear in a space within 5 feet or to remain within the target's corpse. While within the target's corpse, you have total cover and are restrained, and can exit as a bonus action.