Agents Of SHIELD: 10 Best Villains

10. Daniel Whitehall

The team came up against Daniel Whitehall at the top of the second season, a HYDRA agent who had long ago been captured by Peggy Carter herself at the end of World War II. After decades of imprisonment, Whitehall's perseverance paid off thanks to HYDRA's deep infiltration of SHIELD, which allowed him to go free and continue his evil ways.

Thanks to his brutal and - ahem - inhuman experiments on Jiaying, Whitehall was able to restore his youth and reclaim a powerful position in HYDRA's ranks, which he used to brainwash others and pursue the Obelisk. Despite having so many tools at his disposal, though, the slimy, dangerous Whitehall was nonetheless killed by Coulson halfway through the season.

Despite being on the show for a relatively short length of time, Whitehall managed to do a lot with the time he was given, including giving the new HYDRA a real face for the team to rally against in the wake of John Garrett's death and helping to pave the way for the introduction of the Inhumans, an event that is still rippling ever outward even as the show gears up for its fourth year.