There was no sign of Clea (the most famous love interest of Stephen Strange in the comic books) in Doctor Strange, but it sounds like it's possible that the Sorcerer Supreme's protege could show up in the sequel. That's according to writer Jon Spaihts, though it is of course worth noting that he has not been confirmed as returning and a follow-up has yet to be officially announced by Marvel Studios!
Regardless, Spaihts still had something interesting things to say about why Clea wasn't included in the first instalment and weighed in on how he thinks the character could be added to this franchise.
"She’s a tricky character to interpret because her uncle is a kind of fire-headed omnipotent god and she’s kind of a hot babe who studies magic. That’s a tricky relationship to bring out of a comic book and on to a movie screen. But she’s a really compelling character as a foil, a love interest, a colleague of Doctor Strange’s, and she always carries with her that width of mystery as to whether she is human, and how human, and what that means for his relationship to her. So we might find a way to introduce her to the story."
Confirming that he hopes Marvel asks him back for the sequel, Spaihts seems to agree with director Scott Derrickson that Nightmare would be a worthy opponent for Strange. "[Nightmare is] one of the big ones, yes, absolutely! There’s sort of a zombie apocalypse Shuma-Gorath elder god scenario. There’s a kind of unreliable reality Nightmare movie that could be made. There’s a few great things, and of course Mordo is out there, as embodied by the extraordinary Chiwetel [Ejiofor]. He can come back and bring a world of hurt at any time." Those all sound like good options, though it would be nice to see the sequel get a release date first! What would you guys like to see in Doctor Strange 2?