A tip from Manchester leads him and Kara to a recently emptied shipping container and Kara has to stop him from beating answers out of a port employee in episode 4x07 "Rather the Fallen Angel".
A strange duplicate of Supergirl walks out of the snow and encounters a group of Kasnian soldiers in episode 3x23 "Battles Lost and Won". After another training drill, the alternate Supergirl collapses and releases a burst of purple energy while being revived in episode 4x11 "Blood Memory". The Kasnian Minister of Defense calls Lex and asks for his help with their new acquisition in episode 4x16 "The House of L". Appears in 1 more episode.
J'onn sends Kara and that guy off on their space adventure in episode 3x09 "Reign". Winn geeks out over J'onn's spaceship while J'onn is removing the battery needed to recharge the future ship in episode 3x13 "Both Sides Now". J'onn gives Malefic his car so he can travel to Mars and help the resistance and then gets an unexpected visitor in episode 5x08 "The Wrath of Rama Khan".