For my 666th post here, a look back at a previous post of some relevance... How do you fight the Devil?
“How do you shoot the Devil in the back? What if you miss?”
But 666 is more the Antichrist’s mark than the Devil’s Itself, so what place does a prophesied Destroyer have in your game?
Something for the PCs to stop? An obvious classic, the question is at what point they confront him. Cute seven-year-old Damien is emotionally harder to pull a sacred dagger on than fully-clued-in corporate overlord Sam Neill Damien. They might need another way to stop him.
Something for the PCs to be tricked by? Careful this doesn’t come across as a bait and switch, but finding out an ally or employer is Evil Incarnate could be quite a shock. Give them enough time to right the mistakes they made and stop him, of course.
Something for a PC to be? Good Omens is a place to start, of course. Reaper was basically “a Buffy show about a possible Antichrist” - there was a similar RPGnet thread back in Ought-Six. The hero had some demonic powers, but he also had free will. And he had competition, because the Devil isn’t the type to have just one vitally important half-human spawn, is he?
See also the more serious (but soapy) version Point Pleasant. I believe a classic CRPG, possibly Diablo, had the default PC as one of these.
And Hellboy and Marvel’s Son Of Satan for a heroic rebellious Antichrist. (Where’s my reprint of the Warren Ellis run, eh? Grrr.) In a superhero-y or urban fantasy universe, being the spawn of Lucifer is just another way to have powers if you’re part of a team, and might lead to a big event storyline if you’re important enough.
An entire party of Antichrists is possible too - all the PCs are devil spawn of one kind or another. Tieflings in D&D have this, and the demonic Houses from Demon: The Fallen could provide ideas as well. The snarling warrior, the silver-tongued negotiator and the creepy scholar could share parents or grandparents, like Ray Bradbury’s Elliott family. It would certainly be an interesting shared origin for a hero team...