When do I fight Satan?
Solution 1:
As the wiki article about Sheol says, you can enter Sheol and fight Satan if you get a devil room after defeating Mom's Heart. Once you beat Mom's Heart 10 times, you will always be given the option to enter Sheol.
As the wiki article about Sheol says, you can enter Sheol and fight Satan if you get a devil room after defeating Mom's Heart. Once you beat Mom's Heart 10 times, you will always be given the option to enter Sheol.