This post contains SPOILERS for Doctor Strange.

The MCU’s newest superhero outing will be upon us soon as Doctor Strange premieres this November, and there’s already been a ton of buzz about the film’s casting choices. From Tilda Swinton as the Ancient One to taking the character of Wong out of the film entirely and then deciding to put him back in, the cast has been scrutinized more thoroughly than even Heimdall could. Comic readers were also a little perplexed at why it seems as if Strange’s nemesis Baron Mordo (Chiwetel Ejiofor) is his buddy in the movie. Director Scott Derrickson already explained a little bit about why they made that decision, and now Ejiofor has elaborated on his character’s shifting motivations.

Originally, Mordo is introduced as a villain who wants to kill the Ancient One, with hardly any backstory given. Talking to Collider about the movie, Ejiofor answered some questions about how his interpretation of Mordo differs from the version in the comics.

The source material was very helpful in terms of trying to construct an overall understanding of him and his relationship to the place, Kamar-Taj, and his relationship to the Ancient One. Of course in the source material, it’s a much more two-dimensional story in some ways. But one of the richest things of this is finding the other space and really trying to create something that’s very three-dimensional and a person who has a real history and a real background and, as in the comics, has a very good relationship with Kamar-Taj and the Ancient One and by extension Strange himself. So I definitely thought about the character in terms of comics and really understanding the ways in which the character changed and still keep the essence of who he is and add this more three-dimensional aspect to him.

According to Ejiofor, Mordo has a depeer relationship to the Ancient One in the movie than in the comics, which makes his inevitable turn that much more tragic.

I don’t think of him as a kind of envious or jealous entity. I think he’s much purer than that. That’s what I mean by the comics create a slightly more two-dimensional aspect. But the place, Kamar-Taj, what it means and what it means to Mordo, is so strong and his defense of it is so deep and his loyalty is so committed–to the ideas of Kamar-Taj, to the reality of Kamar-Taj, and to the Ancient One that he would react to any perceived threat but it wouldn’t come from a place of envy but from a place of protection and loyalty.

Doctor Strange also stars Benedict Cumberbatch, Tilda Swinton, Rachel McAdams, Benedict Wong, and Mads Mikkelsen, and hits theaters November 4.