"Doctor Strange 2" is not official yet, but considering its success in the box office (it passed "Ant-Man," which is getting a sequel), Benedict Cumberbatch is expected to suit up for a second solo outing.

Director Scott Derrickson already has an idea for the sequel, particularly the villain that Doctor Strange will take on. "I really like the character of Nightmare and the concept that the Nightmare Realm is a dimension, the filmmaker told IGN.

"That's early—that's like the first Strange tale. I think that's in the introductory episode of Doctor Strange, and I always loved that," he went on to say.

Nightmare was introduced in the comics alongside Doctor Strange back in 1963. He was the ruler of the Dream Dimension, which is the place where humans go while sleeping.

The end of the first film also hinted of a sequel as it sets up Mordo's (Chiwetel Ejiofor) turn as the next baddie set to minimize the population of sorcerers in existence.

However, it is to be pointed out that Marvel has not made an announcement about "Doctor Strange 2" happening, and even if there will be one, it will be a while before it comes out as Marvel Studios has films up to 2018.

What's confirmed at the moment is that Cumberbatch reprising his role not in the sequel, but in "Avengers: Infinity War."

At the end of the credits for the first film, the words "Doctor Strange will return" flashed. Derrickson confirmed to Digital Spy that these words referred to Sorcerer Supreme's appearance in "Avengers: Infinity War" in 2018.

"You'll see him in there. But hopefully for Doctor Strange 2," the director said. Doctor Strange is also rumored to appear in "Thor: Ragnarok" as hinted in the mid-credits scene.

If this will be the case, Cumberbatch will be back as Doctor Strange earlier than expected with the third Thor film slated for July next year.