Justice League Unlimited - Season 2 - Eps 3: The Doomsday Sanction
Superman battles Doomsday in the heart of a volcano. Doomsday is revealed to be a modified clone of Superman. Batman probes the Cadmus conspiracy to destroy the Justice League.
About Justice League Unlimited

Title: Justice League Unlimited
First Air Date: 2004-07-31
Last Air Date: 2006-05-13
Status: Ended
Rating: 8.26/10 (from 791 votes)
Language: EN
Seasons: 3
Total Episodes: 39
Network: Cartoon Network
Genres: Animation, Action & Adventure, Sci-Fi & Fantasy, Kids
Production Companies: Warner Bros. Animation
Synopsis
The galaxy's most powerful superheroes return to battle the allied villains and criminal plots that endanger the universe.
Cast

Kevin Conroy
Batman (voice)

George Newbern
Superman (voice)

Susan Eisenberg
Wonder Woman (voice)

Carl Lumbly
J'onn J'onzz (voice)

Phil LaMarr
Green Lantern (voice)