It looks like the Thinker won't be the only mentally-powered villain on season 4 of The Flash; Deadline now reports that the CW superhero show has cast Kendrick Sampson (How To Get Away With Murder, The Vampire Diaries) in a multi-episode arc as DC villain Brainstorm/Dominic Lanse.
Deadline describes the character as "an affable TSA Agent who becomes the unwitting recipient of meta-human powers. Now Dominic bears the gift and curse of reading people’s thoughts, whether he wants to or not." In the comics, Brainstorm also frequently clashed with Mister Terrific, who currently appears on Arrow.
Brainstorm will be introduced during The Flash's winter finale.