A week after announcing the two characters will be appearing during season 4 of the CW’s Arrow, actors have been cast to play the DC characters Mr. Fantastic, and Anarky.

The role of Mr. Terrific has gone to Echo Kellum. A lesser known figure in DC comics history, there have been two versions of Mr. Terrific. The first debuted in Sensation comics #1 in 1942 as the alter ego of self-made millionaire Terry Sloane (DC comics really loved rich superheroes), he possessed Olympic-level athletic ability, a genius intellect and photographic memory, along with extensive martial arts expertise. The second version of the character, Michael Holt, took over the mantle from the original in 1997. Possessing similar intellect, physical ability and martial arts skill, he also has advanced technology built into his costume. The Arrowverse version is named Curtis Holt and is described as a gifted tech whiz working for Palmer Technologies under Arrow‘s Felicity Smoak.

Anarky, meanwhile, will be played by Alexander Calvert. The character, introduced in 1989 as a recurring Batman antagonist, has gone through several tonal changes in the year since but generally, he’s a radical anti-statist whose tangential political interests (environmentalism, populism, libertarianism, and so on) have shifted depending on the writer’s inclinations. On Arrow, he’ll be an elite criminal for hire.

Calvert is repped by Mary Falcon at Play Management; Kellum is repped by Jason Hyman at TalentWorks.