User blog comment:Deadstroke99/WHO''S READY FOR DOOMSDAY!!!!!??????/@comment-1330227-20170925160921

The clue on that baby was that it'll Reign, aka the New 52 Supergirl villain Reign. Also, if they did have doomsday kill Superman on this show, it would likely be either the midseason finale or the finale. Though if he does kill Supergirl, it could be that Supergirl's death is the midseason finale (like Arrow) but that would be too much turn around time before Supergirl's death.