Satan. Yes or Maybe?

Everyone know the story of how Satan fell from Heaven to Earth because He wanted to challenge God and even be greater than God, so Satan decided to raise an army of angels that fell with him to try and take on God and hit God where it hurt the most, His children. Ever since then Satan has been leading Christians astray and trying to have them end up with the same fate, an eternity in Hell. But what if Satan saw the error if his ways? What if one day he decides that there is only one God and that there will always be one God, and wants to be saved and go back to Heaven, could He? Would God forgive Him, or would Satan still be confined to the same fate?