Agents Of SHIELD: 10 Characters Who Should Return In Season 4
4. Ian Quinn
Last Seen: Parting ways with HYDRA - with Gravitonium in hand - in the first season finale, 'Beginning of the End'.
It's surprising that we haven't heard or seen from (or about) the slimy Ian Quinn since he slipped out of the picture, considering how heavily he figured into the series' first year. He managed to get away without punishment despite causing a number of problems for S.H.I.E.L.D. and the team throughout the season, including such terrible things like shooting Skye and leaving her to die, and having a hand in Mike Peterson's mutilation and rebirth as Deathlok.
With two seasons having now passed since he was last seen, Quinn is undeniably one of the series' greatest loose ends, long overdue for a return. Ideally, the silence left in his wake is just there to make his reemergence all the more impactful and surprising rather than simply a result of those behind the series having moved on from the character, especially since his return has the potential to pack quite a punch if paired with another character elsewhere on the list...