Lazarus
ReadyHave 4 or more soul hearts at the same time.
Achievement
Defeat Delirium as Tainted Lazarus.
Sources:AchievementsThe VoidDelirium
Have 4 or more soul hearts at the same time.
Defeat Mom.
Reach Depths II and defeat Mom.
Sources:AchievementsWomb
Defeat Mom's Heart 10 times.
After: The Womb
Defeat Isaac 5 times.
After: The Womb
Defeat Hush 3 times.
After: The Womb, Blue Womb
Defeat Hush.
After: The Womb, Blue Womb
Defeat Mother.
After: A Secret Exit
Open the hidden closet in Home as Lazarus.
After: Lazarus, The Polaroid, A Strange Door
Defeat Delirium as Tainted Lazarus.
After: The Enigma, The Womb, Blue Womb, New Area