“Justice League Unlimited” (JLU) only had three seasons, and the first episode of Season 3 is “I Am Legion.”
Justice League Unlimited Season 03 Episode one Part 01
Justice League Unlimited Season 03 Episode 01 02
Justice League Unlimited Season 03 Episode 01 03
Justice League Unlimited Season 03 Episode 01 04
Lex Luthor, now a fugitive from the Justice League, is recruited by Gorilla Grodd to join the newly formed Legion of Doom. Meanwhile, the League, including Flash, Hawkgirl, and Shayera, try to stop Luthor and his new allies from stealing an ancient artifact from Blackhawk Island.