Just when The Lord of the Rings: The Rings of Power reveals the identity of one mysterious wizard, it brings in a new mysterious mage for us to puzzle over.
Season 1 introduced us to the Stranger (Daniel Weyman), a powerful figure with no recollection of who he is. Based on a key quote in the Season 1 finale and a new hint in Season 2, episode 2, it's fairly clear to the audience that the Stranger is Gandalf the Grey. But he has no way of knowing that! So it's off to the Eastern land of Rhûn for the Stranger, where he hopes to find answers about who he is and what role he has to play in the battle to come against Sauron (Charlie Vickers).
But before the Stranger can worry about the Dark Lord, he'll have to deal with another villainous entity: a Dark Wizard (Ciarán Hinds) who's set up shop in Rhûn. In Season 2, episode 2, we learn that it was this Dark Wizard who was responsible for sending the white-cloaked Mystics after the Stranger in Season 1. He also seems to be a fan of both moth magic and blood magic, but otherwise, we don't know much about the Dark Wizard — not even his real name! Just like with the Stranger's identity in Season 1, though, we can definitely make some educated guesses as to who from J.R.R. Tolkien's legendarium the Dark Wizard might be.
The biggest clue here is the "wizard" of it all, which suggests that the Dark Wizard is an Istar like the Stranger. Appropriately meaning "Wise One" or "Wizard," the Istari are a group of five powerful spirits known as Maiar whom the Valar sent to protect Middle-earth.
Three of the Istari feature fairly prominently in Tolkien's work: Gandalf the Grey, Saruman the White, and Radagast the Brown. However, The Rings of Power's Dark Wizard really can't be any of these three. The show has indirectly confirmed time and again that the Stranger is Gandalf, so that's him ruled out. Saruman does eventually fall to the darkness in The Lord of the Rings trilogy, but his turn occurring in the Second Age, when The Rings of Power takes place, would be far too soon. Finally, nature-loving Radagast is probably too busy hanging out with the animals of Middle-earth to even bother raising a cult of moth-wielding Mystics.
So that leaves us with the last two Istari, and the ones Tolkien tells us the least about: the Blue Wizards, otherwise known as Ithryn Luin, named for the color of the robes they wore upon arrival to Middle-earth.
The Blue Wizards are a big question mark in Tolkien's legendarium, perhaps even to Tolkien himself. In one of his 1958 letters, he wrote, "I really do not know anything clearly about the other two [Istari]." In the Unfinished Tales, there are mentions of them being named Alatar and Pallando. In later works, though, he referred to them as Morinehtar and Rómestámo.
These later writings clarify a bit of what Tolkien believed to be the purpose of the Blue Wizards, which was to curb Sauron's rise in the East. And you know what's in the East? Rhûn, right where the Dark Wizard is hanging out. Based on that alone, it's pretty likely that the Dark Wizard is one of the Ithryn Luin.
There's even more evidence for that theory, though. In the same letter where Tolkien said he didn't know too much about the Blue Wizards, he theorized that they were "emissaries to distant regions" who "failed, as Saruman did" and fell to darkness. From there, Tolkien "suspect[ed] they were founders or beginners of secret cults and 'magic' traditions that outlasted the fall of Sauron." And I don't know about you, but the Mystics and their moth magic feel very much like a secret cult to me.
Of course, there's the the small problem that the Dark Wizard's robes and surroundings are devoid of anything blue, which doesn't exactly scream Blue Wizard. But perhaps he simply rejected the color associated with his original mission to Middle-earth when he turned evil, ditching the blue for his current look. After all, if Sauron's shift from Halbrand to Annatar taught us anything, it's that Middle-earth villains love a makeover.
