|Any floor up to The Womb I, except The Depths II|
The Fallen is a boss that, similarly to the The Headless Horseman, can appear as the boss of any floor before The Womb II, except The Depths II. He also can appear as a normal enemy on floors after The Womb, and will always spawn before the Satan battle.
Upon entering the battle, The Fallen is a single demon with two main attacks. The first attack is shooting tears in two pattern in a burst of two shots. The first shot has three tears, the second has four. He can also yell and begin charging for Isaac. When he gets damaged enough or runs for enough time, he will stop and shoot brimstone in four directions.
When The Fallen is halfway dead, it will split into two smaller forms. They each share half of the remaining health bar. Their attacks are exactly the same, but now much more deadly due to having to dodge both at once.
Charming effects are especially effective on this boss' second form. Causing one to Brimstone the other will kill them extremely quickly.
- The Fallen drops items from the Devil Room item pool rather than the boss pool. They cost no heart containers to pick up. Devil Rooms can still spawn at the end of the boss fight.
- Rerolling the drop from the Fallen will reroll it from the devil's room pool.
- This boss is the first phase of the Satan boss fight.
- Picking up the devil room item wont prevent angel rooms to spawn.