Villains Metallo & Livewire from Supergirl's past will be returning in 2017.
Russ Dimino looks at the history of the Supergirl and Superman villain Metallo.
Screen captures from the extended promo trailer for the Supergirl episode "The Last Children of Krypton"
Supergirl and Superman will both be fighting Metallo in Season 2 of the CW series.
