Agents Of SHIELD: 10 MIA Characters Who Should Return

4. Deathlok

Last Seen: Discussing bodily repairs with Fitz and Simmons following his capture and torture by HYDRA in Season Two's "The Dirty Half Dozen." Mike Peterson has been a part of the series from its very first episode, going from Extremis-afflicted father to an emotionless, cybernetic puppet to hero and valuable team ally. With so much having gone down since his last appearance - Jiaying's plans, the Lash hunt, Ward still being Ward - it's a surprise he hasn't turned up to help. He's grown to be an interesting part of the series, and one whose appearances provide something to look forward to, especially when they're unexpected, like his cheer-worthy rescue of Coulson and Hunter from Gonzales' men. Even if he doesn't join the Secret Warriors, more Deathlok - locked and loaded with new upgrades, no less - is always something the show can use more of.