It has been heavily rumored but not officially confirmed that Wood will be playing Mon-El, once thought of as “Superboy’s brother” who first appeared in Superboy issue #89 back in 1961.
Mon-El actually isn’t Kryptonian; he has powers a lot like a Kryptonian, but he is actually from the planet Daxam. He also has a different weakness: Lead.
Hopefully we will learn more, including an offical confirmation of his character’s identity, soon. Season 2 of Supergirl premieres October 10 on The CW.