|Floor(s):||The Chest or The Dark Room|
|Attacks:|| Summon Harbingers|
Summon Super Seven Deadly Sins
Summon Fallen Angel
Summon Seven Deadly Sins
Shoot fire streams
Two color bullet hells
|Unlock:||Defeating ??? (boss) or The Lamb|
He shoots out straight lines of blood that curve to the right, and alternate to the left, like the Wiggly Worm. (See right)
- He slams down one of his fists making a rocky shock wave that moves forward.
- He shoots a giant Brimstone beam out of his mouth straight ahead.
- He starts breathing yellow and purple fire that bends towards the player.
First StageEditHis main attack is to spray shots in interlacing streams for a few seconds, and then fire waves of earthquakes at you. Later he also has a massive brimstone beam.
After a while he summons two the four horsemen, Famine and Pestilence, followed by War and Death. After you damage him some more he summons the seven super sins, first Super Envy, then Super Lust and Super Wrath, then finally Super Sloth, Super Pride, Super Gluttony and Super Greed. Defeat them and return your attention to Mega Satan, upon taking more damage, he summons the two fallen angels that were defeated to obtain the key pieces, one at a time.
After Mega Satan's first form is defeated, he will reappear as a demonic skull. During this phase, he can spew streams of different colored bullets in varying patterns, or he can spew streams or bursts of fire. As Mega Satan takes more and more damage in this phase, his skull will begin to slowly crack more and more until he is defeated. When defeated, he will sink into the ground once more and end the fight.