After the events of the previous film, Superman is controversial figure as the world's governments debate over his actions. This leads to US government funding an anti-Superman military research, spearheaded by Lex Luthor who maintains a humanitarian, selfless hero facade, while harboring strong resentment against Superman and his public support as he considers him to be a dangerous extraterrestrial being who can't be stopped if he turns against humanity. He manipulates both the government and Superman into believing him while pushing his plan to get rid of Superman. He uses a survivor of the Battle of Metropolis for his cybernetic body enhancement armor project , Metal-0 and uses him as his weapon against Superman. Meanwhile Superman crosses paths with Batman , who suspects Luthor for funding illegal metahuman research in Gotham and Metropolis. Superman has to prove his hard earned trust and allegiance to humanity before Luthor and Metallo tarnish it beyond repair.
