When Superman makes his way to Supergirl this fall, the Man of Steel will be facing off against one of his oldest foes from the comics. EW has learned exclusively that Frederick Schmidt has been tapped to play Metallo.When international assassin John Corben is badly injured after taking on both Supergirl (Melissa Benoist) and Superman (Tyler Hoechlin), he is reborn by a shadow organization into the Kryptonite-powered supervillain Metallo.Superman’s adversary first appeared in Action Comics in 1959, but has been showcased in many iterations — all usually involving some form of Kryptonite-powered suit or cybernetic enhancements. Smallville fans may recall that Brian Austin Green took of the mantle of Metallo in season 9.Metallo will appear in at least two episodes, starting with the season 2 premiere, airing Monday, Oct. 10 at 8 p.m. ET on The CW.