After clearing so many rooms of hell, you come across the boss room, possibly the final fight. You step in and are met with.. a blue thing that looks like you? You wonder why its curled in a ball, and suddenly, it gets up and wings form out of its back, and alas, the fight begins. ???: "Better luck next time, Isaac." It shoots a homing tear at you, unexpectedly. Ouch. ???: "This is your final fight."