TV Smallville alum Sam Witwer joins Supergirl season 4 as Agent Liberty By Chancellor Agard Chancellor Agard Chancellor Agard is a former staff writer at Entertainment Weekly. He left EW in 2022. EW's editorial guidelines Published on July 17, 2018 05:00PM EDT Photo: Joel Aron; DC Comics Supergirl has lured in yet another Smallville vet! Sam Witwer, who starred on Smallville season 8 as Doomsday, has joined the CW superhero drama’s upcoming fourth season in the series regular role of DC Comics character Agent Liberty. In the show’s interpretation on the character, Agent Liberty is the ruthless and terrifying founder and figurehead of Children of Liberty, a hate group that supports a human-first world order. According to a description from the show’s producers, he’s “a brilliant orator in the guise of a family man” and the scariest thing about him is how easily he can convince people that he’s right. Given that Supergirl (Melissa Benoist) and the DEO tend to be pro-alien integration, it’s definitely fair to assume they won’t get along with Agent Liberty and his Children of Liberty. At this point in Supergirl‘s run, Witwer isn’t the first Smallville alum to appear on the show. Erica Durance, who played Lois Lane for seven seasons, recurs as Kara’s mother Alura Zor-El, and Laura Vandervoort, who played Supergirl on Smallville, guest-starred as Indigo in season 1. In recent months, Supergirl has undergone several cast changes. Series regular Chris Wood and Jeremy Jordan both left the series at the end of season 3; however, Jordan is expected to recur in the new season. Meanwhile, Jesse Rath, who stars as Brainiac 5, was promoted to series regular for season 4. Witwer’s other credits include Star Wars: Rebels, Once Upon a Time, and the U.S. version of Being Human. Supergirl returns Sunday, Oct. 14 at 8 p.m. ET on The CW.