Even though Superman & Lois season 3 already boasts two major DC Comics villains, there's a chance a third, unannounced character will factor heavily into the battles to come. It's been confirmed that Superman & Lois season 3 will see Superman contend with both Lex Luthor and Bruno Mannheim. But whether or not one or the other is the season's main antagonist has yet to be confirmed, and may not be become clear until several episodes have aired.
https://screenrant.com/superman-lois-season-3-secret-villain-prediction/