Some Christians believe that today is Satan's birthday. Actually, nobody knows when Old Scratch was born, but there is a 1 in 365 chance that it was on October 31. So I am willing to celebrate it today.
Satan is a complicated character: adversary, light-bringer, composite of older repressed gods.
What actor would turn down a chance to play the Devil? Have you seen the original Bedazzled with Peter Cook playing George Spiggot, Prince of Darkness? (I didn't see the remake, so I don't know if it was any good. Anyway, I don't think you should remake good movies. Remake bad movies and do a better job.) He buys Dudley Moore's soul, then puts him through a series of hilarious mishaps. So if you haven't seen it, get it now and spend this evening watching it.