Rath will recur in multiple episodes as the longtime member of the Legion of Super-Heroes, who in this incarnation will be a half-computer, half-organic being from the 31st Century who travels to present-day National City to help Supergirl (Melissa Benoist) and the DEO battle Season 3’s Big Bad, Reign (Odette Annable).
In the comic books, Brainiac 5 has a long-running crush on Supergirl and showrunner Andrew Kreisberg previously teased a new character coming into the season who “will like Kara a lot, which will be a lot of fun.”
There’s no indication that Kara will return those feelings, of course, but she is single now after the exit of former love Mon-El (Chris Wood), though surely we can expect he’ll be back at some point. Supergirl fell for Brainiac 5 in at last one other adaptation, the animated series Justice League Unlimited, where she opted to stay in the future in order to be with him.
Brainiac 5 will make his debut in the 10th episode of Season 3, titled appropriately, “Legion of Super-Heroes.”
Supergirl airs Mondays at 8 p.m. ET on The CW.