Complex sentence: The human hosts work as unwitting sleeper agents for former Justice League associate Maxwell Lord, who controls Brother Eye and uses the OMACs to stalk and attack the world's superheroes and supervillains.
Split into simpler sentences: The human hosts work as unwitting sleeper agents for former Justice League associate Maxwell Lord, who has assumed control of Brother Eye. Lord uses the OMACs to stalk and attack the world's superheroes and supervillains.