It's not a secret that a Doctor Strange film is in pre-production. Benedict Cumberbatch has been signed up to star as the Sorcerer Supreme, and Cumberbatch is no stranger to TV acting from his stints as Sherlock Holmes. With these facts in mind, it is not impossible that Cumberbatch could be brought in as the linchpin of the Defenders mini-series. He doesn't even need to be in much of it: his character could operate remotely from his Sanctum Sanctorum for the most part, only stepping in directly at the end. In addition, having a magic user in the team is a good way of having variety in the mini-series. The magical aspects don't absolutely require costly special effects; magic can be low key, done with just a few words, with the effects shown without a big production. However, if Doctor Strange turns out to be too costly a character, fellow Defender, Moondragon, would be an excellent substitute. Her comic-book plots included a powerful story of a journey to the dark side, which could be a great central conceit for the mini-series.