Satan is one of the main characters in the comic. He is depicted to be the son of God and a fallen Angel. Since he was exposed to sin and evil for such long periods of time, physical manifestations of hatred and lies expressed themselves as horns, ears and possibly limbs. He can shape shift to any human form, and may be able to change his Satan form (e.g. Have satyr legs.)
He has a very mischievous personality and is willing to do anything to get people to sin and often acts on those ideas of blasphemy. But, he does retain some traits of his angelic past, as he likes to play around with Nat at times and those games being innocent.e.g.link He doesn't hesitate to reveal his true identity though, as seen here even if it might cause concern to his Master. This behaviour may be caused because he considers it not to be troublesome to himself in particular.
He and Natalie share somewhat of a friendly relationship, though he still shows that he hates being trapped in a girly room with pretty much nothing to do, possibly until Natalie's death. It should be noted that a pact made between a person and Satan runs deeper than the closest of family bonds, but we have yet to see that bond kick into action. It's heavily believed that if Natalie hadn't accidentally made a contract, he would have done more than a few petty pranks here and there. Even so, Satan likes to play around with Natalie and is seen to be enjoying his stay sometimes. Their relationship is reluctantly (on his end) continuing to grow. Satan is also shown to be very protective over Natalie, threatening physical violence towards anyone who intends to harm her.
While his actions towards Michael are very mixed, Orangeplum has said that Satan hates everyone and anyone named Michael because "It's kind of a trigger to his own bad memories with his brother, the Archangel Michael. So anyone named Michael is not his favorite."
However, it can be said to Satan's credit he has not used Mike's crush against him in comic so far.
Michael and Satan have a very rough relationship between the two of them, though they used to be very close. Before Satan fell, he and Michael were shown to have a friendly relationship, though, according to Archangel Raphael, they always bickered even in Heaven. Their close bond was shattered when Satan decided to fall from Heaven, which they both are not eager to recall the memory. Now, upon seeing each other, Michael and Satan will usually argue or get physically violent with one another. It is shown that Michael is afraid of fighting Satan, and Satan, despite hating his brother, has no desire to mindlessly kill him.
- The color of Satan's horns correspond roughly to how he's feeling. They turn more gold when he's surprised or in a good mood while turn red or crimson when angry, frustrated etc.
- Satan has been revealed to have the ability to heal, though not to the level Angels are able, and when demonstrating this ability glows, hands emitting rainbow colors.