Jesse Rath, who recurred in Season 3 of Supergirl, has been promoted to series regular for Season 4 of the CW series.

Rath plays Brainiac-5. Half computer, half organic life and boasting a 12-level intellect, Brainiac 5 is a member of the Legion of Super-Heroes who travels to National City from the 31st Century to help Supergirl and the DEO battle Reign (Odette Annable).

Courtesy of Hess Entertainment

Rath appeared in five episodes in Season 3, which airs its season finale on Monday, June 18.

“We love the character of Brainiac-5 and can’t imagine anyone but Jesse Rath in the role, said executive producers Robert Rovner and Jessica Queller. “He brings such fun, heart and brilliance to Brainy and we’re so excited he’s joining the cast as a series regular for season 4. We have a lot of great Brainy stories to tell.”

In the third season, Kara (Melissa Benoist) is grappling with the sacrifices she’s made and deciding if she should give up her human identity altogether. Being human and vulnerable is hard. Maybe she’s better off embracing her alien DNA and only being the “Girl of Steel.” As Kara struggles with her path forward, she continues to work with the DEO to battle all threats to National City, including new villains Morgan Edge (Adrian Pasdar), and the “Worldkiller,” known as Reign (Annable).

Rath is known for his previous work on No Tomorrow for the CW and Syfy’s Defiance. He’s repped by SDB Partners, Amanda Rosenthal Talent and Hess Entertainment.

Supergirl is produced by Bonanza Productions Inc. in association with Berlanti Productions and Warner Bros. Television. Greg Berlanti, Jessica Queller, Robert Rovner and Sarah Schechter executive produce.