When Tilda Swinton was cast to play the Ancient One in Marvel's Doctor Strange film, it caused some people pause. In the original comics, the Ancient One is depicted as a Tibetan man, most often depicted with a wise-looking beard. In other words: the Ancient One was not, and had never been, a white woman. Early trailers of the film raised even more eyebrows, but, after seeing the movie, it's likely fans of the comics will have a very different bone to pick with Doctor Strange's portrayal of the Ancient One — regarding the character's fate. Spoilers ahead! In Doctor Strange, the Ancient One dies, an event that deviates greatly from the comics. The character seems to accept her death as absolute, but is the Ancient One really dead in Doctor Strange?
In Doctor Strange, both the comics and the film, the Ancient One is introduced as an ageless being. She has been alive for centuries, acting as Sorcerer Supreme of Earth, protecting the planet from mystical threats and training sorcerers, like Doctor Strange. In the film, it is revealed that the Ancient One has been using dark magic to lengthen her life, and, after a particularly brutal fight with the villain Kaecilius, she dies, seemingly for good. In her astral form, she says goodbye to Doctor Strange, admits that she has never seen her future beyond this moment, and fades into nothing. The fact that she tells Strange that she believes this to be her time to die suggests that the Ancient One is truly dead, but the nature of magic tells me that perhaps viewers shouldn't really trust everything we see.
The Ancient One's death might not be permanent. In the comics, the Ancient One does fake her own death, though under completely different circumstances. So, there is precedent for the Ancient One to come back to life, not to mention Marvel's long history of faking deaths (Nick Furry, Agent Coulson). Furthermore, the film takes great pains to separate the soul from the body, meaning the Ancient One's soul could be alive, but simply in hiding. Or, death for the Ancient One could simply be a trip to an alternate dimension Doctor Strange has yet to visit.
Even assuming the Ancient One really is dead, that doesn't mean this is the last we've seen of Tilda Swinton's Marvel character. Marvel is notorious for giving actors multiple movie contracts, meaning Swinton could be contracted to appear in more films. She could appear in dreams, flashbacks, or come back from the dead. She could even appear in non-Doctor Strange Marvel movies. Speaking of the possibility of life beyond Doctor Strange, Swinton revealed that she is just along for the ride. "Who knows where one might pop up. I don't know where they'll use me and I don't know that they know," she said in an interview with ScreenCrush.
In a more recent interview, Swinton said she wanted to reprise her role as the Ancient One in a potential prequel. So, if the Ancient One really is dead, it's not going to get in her way. "I'm pretty confidently dropping hints in [Marvel Studios President] Kevin Feige's ear about a prequel, I'm constantly harassing him about that," Swinton told ScreenCrush in a separate interview. The Ancient One may be dead, but, if the actor has her way, that won't stop her from coming back to the big screen. The only question is when.