Mother begins the fight attached to the top of the room and is stationary. Walking into it drops Isaac down into the arena where Mother is fought. Upon entering the boss room in Corpse II, the room is empty except for a hole in its center. Mother is a boss added in The Binding of Isaac: Repentance and the only boss of the second floor of the Corpse, as well as the final boss of Ending 21. If objectives are completed in Hard mode, the completion marks are outlined in red. If objectives are completed in Normal mode, the completion marks are solid black. As you complete these objectives, the post-it note on the character select screen fills up with Completion Marks. I beat mother after going past -500.Completion marks are earned by completing specific objectives in The Binding of Isaac: Rebirth. Ghost pepper and birds eye are your holy grail for mother (besides the obvious psy fly) Good luck finding spindown dice and good luck finding an item that you can spindown into psy fly on the same run. Tainted lost, trying to get the mom completion.
