According to the Damned Souls Orientation Guide audio tapes Satan left around Hell, following Satan's fall from God's grace, Satan fell into Hell, which was once just a time out zone in the afterlife. Using his anger, Satan twisted Hell into what it is today. Overtime, Satan would plot revenge on God and planned to invade Heaven again and again. He had an army of demons at his disposal, and even recruited damned souls to be part of his army. He would not tolerate failure, seeing it as unforgivable.
During the events of Saints Row IV, when Zinyak killed off a majority of humanity, Satan managed to collect his share of souls, while Heaven was still collecting it's share in a slow orderly fashion. As a result, Satan had enough souls to plan a new invasion.
Sometime after the defeat of Zinyak, during Kinzie Kensington's birthday, the Third Street Saints play with the Oujia Board, and unwittingly contact Satan. Satan kidnaps the Leader of the Saints in order to force his daughter Jezebel into an arranged marriage. This leads to the Boss' two friends Kinzie and Johnny Gat to go into Hell to rescue the Boss, and with Gat promising to "shoot the devil in the face".
It turns out Satan kidnapped the Saints leader was to make him his general for his next invasion. Satan and Jezebel argue over it, and when she's defiant, Satan reminds her that she belongs to him and he's giving her away. Johnny and Kenzie team up with Dane Vogel and other souls in Hell to get Satan's attention and kill the Archdukes of Hell. Jezebel approaches Johnny and offers to take him to Satan's palace. There, Johnny immediately confronts Satan, who takes his own daughter hostage and threatens to kill her. When Johnny puts the gun down, Satan gleefully and sarcastically boasts to Johnny that he "loves" Jezebel and forcibly makes a deal with Johnny; Satan will release the Saints leaders soul, and Johnny takes their place.
At the wedding, Johnny immediately pulls a gun on Satan and shoots him in the face. Kinzie arrives, she and Johnny fight off the horde of demons and Satan challenges them to a fight. In the fight, Satan ultimately looses, but before he can be finished off, Satan begs for mercy. Unable to handle the indignity of being beaten by a mortal and having a rebellious daughter, Satan banishes Johnny, Kinzie, Jezebel and the Saints leader from Hell back to the mortal coil, but Johnny gets sidetracked by God who rewards him for Satan's defeat.