Warning: The following contains SPOILERS for the Superman and Lois season 3 premiere.The premiere episode of Superman and Lois season 3 featured the surprising appearance of the Green Arrow villain Onomatopoeia, who never appeared on Arrow or in any Arrowverse series. Superman and Lois season 3 already promised to be full of villains, featuring its versions of popular Superman adversaries Lex Luthor and Intergang leader Bruno Mannheim. This made the introduction of Onomatopoeia all the more surprising, particularly given the way the character was changed from the comics to make them a more formidable threat.
Superman and Lois season 3, episode 1, "Closer," also brought back the villain Atom-Man, who was one of the first supervillains Superman ever faced. Atom-Man had been upgraded considerably, however, now possessing real superpowers in addition to his power armor. Atom-Man was seemingly gunned down before he had a chance to finish Superman off, but a quick scan with his X-Ray vision determined that there were no bullets in Atom-Man's body, despite Superman hearing gunshots. The source of the gunshots was Onomatopoeia, who took advantage of Superman's distracted state to disappear with Atom-Man's body. This suggested that Superman and Lois' Onomatopoeia has sound control powers, unlike his comic book counterpart.
