Meg Donnelly as Supergirl / Kara (voice)

Harry Shum Jr. as Brainiac 5 (voice)

Jensen Ackles as Batman (voice)

Gideon Adlon as Phantom Girl (voice)

Matt Bomer as The Flash (voice)

Darren Criss as Superman (voice)

Robbie Daymond as TimberWolf / Brainiac 4 (voice)

Darin De Paul as Brainiac / Solomon Grundy (voice)

Ben Diskin as Arms Fall Off Boy / Brainiac 2 (voice)

Victoria Grace as Shadow Lass (voice)

Jennifer Hale as Alura (voice)

Cynthia Hamidi as Dawnstar (voice)

Ely Henry as Bouncing Boy (voice)

Daisy Lightfoot as Triplicate Girl (voice)

Eric Lopez as Cosmic Boy / Chemical King (voice)

Yuri Lowenthal as Mon El (voice)

Zeno Robinson as Invisible Kid / Brainiac 3 (voice)