BEGIN SLIDESHOW The CW’s Supergirl and Charmed unite in new combo promo The CW has released a new combo promo uniting season four of Supergirl and the new Charmed series reboot ahead of their premiere night on Sunday, October 14. Check out the promo now in the player below! Season 3 saw Supergirl stop Reign and the other Worldkillers’ threat to humanity and our planet, and in the process, Kara was shocked to find her mother Alura alive and living in a salvaged Argo City that survived the destruction of Krypton.