We are first introduced to the idea of a Lupus Dei in S2E1 (39:30), as Hecate talks to her mother, Madame Kali, and calls Ethan the Lupus Dei. It is never explicitly explained how Kali and her coven know that Ethan is the Lupus Dei. We learned that Ethan was a werewolf throughout season 1, and as Lupus Dei in Latin means Wolf of God, it makes sense that the term is referring to Ethan’s ability to transform into a werewolf. However, we still know very little about werewolves or Lupus Dei in this universe. We do not know how Ethan became a werewolf, or if he was simply born with the ability, like Vanessa is a natural born Daywalker.

As Sir Lyle deciphers the Memoirs of the Devil, or the Brother Gregory relics, he comes across the phrase Lupus Dei, which is repeated several times in several different languages. Sir Lyle surmises that the phrase was being repeated so often, because Lucifer knew it was the only thing that could hurt him in his quest for Vanessa. Sir Lyle shares this conclusion with Victor, Malcolm, and Sembene. Sembene is the only one to recognize the significance of the discovery, as he is the only one to have seen Ethan transform. Unfortunately, Sembene was killed before he was able to tell Ethan about the discovery. At the end of season 2, Ethan has not yet made the connection that he may be the Lupus Dei. However, in the cold open to S3E3, Hecate calls Ethan the Lupus Dei, and it is the first time on screen that Ethan makes the connection.

Ethan transforms into a werewolf at every full moon, and it is a transition that he cannot control. He describes the transformation as similar to a blackout, and says that he cannot fully remember what happens, but there is “usually blood”. Whenever Ethan transforms, he feeds on either a human, or an animal. The only exceptions have been when he transforms in S3E2; we do not see him feed on anyone in the tavern, and of course, when Sembene chained him in the cellar. While he is a werewolf he cannot control who he attacks or kills. The only exceptions, so far, have been Vanessa and Hecate. In the season 2 finale, after Ethan (in werewolf form) attacks and kills Sembene, Hecate unleashes him, in the hope that he would do the same to Vanessa. Ethan runs into the enchantment room, where Vanessa and Madame Kali are, and kills Kali with a swipe of his claws. He then goes toward Vanessa, who is scared, but stands her ground. Ethan stops, and looks at Vanessa, with something like recognition in his eyes. When she tries to touch his face, he runs off. Later in the season 2 finale (39:34), Vanessa goes up to her room to find Ethan there. He seems to remember seeing Vanessa while a werewolf, because he says to her, “Now you know what I am”, despite the fact that they have not seen each other or spoken since the incident. In S3E2 (44:35), Ethan transforms into a werewolf, and kills everyone inside the tavern he was in. Hecate was hiding in the wall in her Nightcomer form, spying on Ethan. She sees a man point a gun at Ethan, and kills him, and then kills the bartender. Ethan in werewolf form walks up to Hecate, but does not attack her.

In S2E6, Ethan asks Sembene to chain him in the cellar, and then watch him transform. Sembene does this, and in the next episode’s cold open, he explains to Ethan what occurred. Sembene says the shamans in his village called it Uchawi Mabadiliko, which can be translated roughly from Swahili to mean “magic change”. In season 3, it seems as though both Kaetenay, and a Native American woman who Ethan speaks to in the tavern before transforming, both know what Ethan is. Therefore, it would seem that at least werewolves, and perhaps Lupus Dei, are acknowledged in other cultures around the world in this universe.

Although Lupus Dei translates to Wolf of God, it is unclear if the Lupus Dei is entirely a force for good. In parts of season 2, and throughout the beginning of season 3, Hecate has been trying to convince Ethan to “embrace his sins”, so that she can “rule the darkness at his side”. Kaetenay is also concerned that if he and Sir Malcolm do not reach Ethan in time, they will have to “kill the evil he has become”. Kaetenay remarks that Ethan is “halfway damned already”.