Legion is confusing, you guys. Between David's split personality, and tampered-with memories, it's hard to tell what's real, what's not, and what's going on at any given moment. Thankfully, there's one thing we don't have to puzzle over anymore: the identity of Legion's Yellow-Eyed Demon. Although the exact identity of the show's terrifying villain has been a mystery for most of the season — with some viewers speculating that he could be either Mojo or Fiend/Professor Y — a promo for this week's episode, "Chapter 7," finally confirmed that The Devil With The Yellow Eyes is The Shadow King.
In the promo, the revelation comes during a conversation between Oliver Bird and Cary Loudermilk. "You know what it is? Or should I say who," Oliver asks the scientist, regarding the creature haunting David's troubled mind. "Amahl Farouk," Cary replies. "The Shadow King." But who is Amahl Farouk? Where did he come from? And what does he want with David Haller? Fortunately, unlike most of the characters on Legion, the villainous demon isn't an original creation by showrunner Noah Hawley; which means we can actually look to the source material for information this time. So who is The Shadow King in the Marvel Comics?
Amahl Farouk was first introduced on the page in a 1979 issue of the X-Men series. In that issue, Charles Xavier recalled an encounter he had with a mysterious man in Cairo. While sitting in the same bar, Xavier and Farouk quickly realized each other's ability to communicate telepathically; after a hostile exchange, the evil Farouk attacked Xavier with his mental powers. While the two men sat nonchalantly in the bar, their minds engaged in a fierce battle on the astral plane. Ultimately, Xavier was able to defeat Farouk; Farouk's physical body was killed, but his mind remained trapped in the astral plane. As Xavier recounted, this was his first interaction with an evil mutant, and it was the inspiration that led him to form the X-Men to fight against other super-powered humans with villainous intentions.
Over the next decade or so, the incorporeal Farouk would pop up every now and then and possess the mind of a mutant, wreaking occasional havoc for the X-Men. During this period, he began to be referred to as The Shadow King. This climaxed in the classic 1991 storyline "The Muir Island Saga," in which Farouk psychically took over the mutant research facility on the titular island and, when the X-Men came to confront him, he possessed the mind of Professor X's son, David Haller — also known as Legion.
During this encounter, it was finally revealed that Amahl Farouk himself wasn't actually The Shadow King. In fact, The Shadow King was an entirely separate entity who had possessed Farouk and used him as a vessel to carry out his sinister plans. The mysterious being wasn't even human at all; it was simply a manifestation of the dark side of human consciousness, born into existence during the very first nightmare. Ever since then, it has been lurking in the astral plane and attaching itself parasite-like to powerful human hosts in an effort to gain a corporeal form and take over the world.
After an intense battle taking place simultaneously in the real world and in the astral plane, Professor X and the X-Men finally defeated The Shadow King — but not before Xavier was crippled once more (he had recently regained the ability to walk); and David's possession by astral demon left him in a coma from which he wouldn't reawaken for many months. However, because The Shadow King doesn't exist in any sort of physical form, it has proven impossible to kill. Despite temporary defeats and setbacks, it always returns eventually to wreak even more havoc on the X-Men and the world at large.
Given its long history with both Charles Xavier and David Haller, it's no surprise that The Shadow King (and its human host Amahl Farouk) was chosen by Hawley to be the Big Bad of his show's first season. Now that we know the true nature of The Devil With The Yellow Eyes, the biggest question that remains is: will David's father show up to help him battle The Shadow King? Will Professor X ever appear on Legion? Stay tuned to find out…