Agents Of SHIELD: 8 Characters Who Need To Return In Season 6
5. Donnie Gill
Last Seen: Season 2
With the Gravitonium having finally made its return in season five and given rise to Graviton, the fate of Donnie Gill is now one of the oldest loose ends the show still has left to address. After his introduction in season one, which saw him gaining the ability to freeze things, Gill was shipped away to S.H.I.E.L.D.'s Sandbox, where HYDRA ultimately trained him to use his powers, brainwashing him in the process.
When he returned in season two, he was in hiding from HYDRA, who inevitably tracked him down in an attempt to bring him back into the fold - voluntarily or not - and during a clash between S.H.I.E.L.D. and HYDRA, a brainwashed Gill was ultimately shot by Daisy. His body tumbled into the ocean and sank, freezing along the way, and the only follow-up we've ever received since has been that his body was never found.
At this point, it's hard to see Gill resurfacing as a major villain (or even at a villain at all) considering all he wanted to do was hide, but for the sake of closure, particularly in terms of making peace with Simmons, who he last believed was working for HYDRA, his return would be a welcome one.