Brainiac returned in the "Panic in the Sky" storyline after seizing control of the mobile planetary fortress Warworld and recruiting assistance from Maxima and the alien warrior Draaga. Discovering a lost and confused Matrix (an artificial life form who at this time operates as Supergirl), Brainiac brainwashes her into becoming his soldier. He clashes with the New Gods and then launches a pre-emptive strike on Earth. Rather than wait for an invasion, Superman gathers a large group of superheroes and allies, one team attacking Warworld directly while the other remains on Earth to counter further attacks. Through duplicates of his braincase, Brainiac briefly takes control of some of Earth's heroes, but ultimately he fails. Supergirl and the other heroes are freed from mental control and the villain is rendered catatonic. His vegetative body is taken back to New Genesis for observation.