7. Agent Crimson
Agent Crimson would be a very interesting character to see in Agents of S.H.I.E.L.D, as he is the head of S.H.I.E.L.D.'s Magic-Ops Division. He has been a part of the "Hulkbusters" before, but is now a more magic-focused character, investigating magical issues and characters and that would be great to see brought to the Marvel Cinematic Universe - it would be a cool way to gradually introduce Doctor Strange in time for his titular film. Agent Crimson has several magic powers of his own. Being a devout follower of Cyttorak (the powerful entity that provides characters such as Juggernaut with their power), these include spells such as the Crimson Bands - magical wraps which encase their victims which have been used by such characters as Doctor Strange, Doctor Doom and Dormammu. Even if Agent Crimson isn't focused on, just seeing him on screen and knowing he existed would be a nice little Easter egg to confirm that S.H.I.E.L.D are investigating magic (which would make sense, given that they've encountered the likes of Loki in the MCU).