So far most of us know that Darkseid will return as the main antagonist since he as DC's most powerful villain has showed up working with Vandal Savage and since many of us have waited so long for the show to continue after it was cancelled with plotholes regarding the members of the Light still at large and while we are hoping that Greg Weisman does not stall from having the team take down and apprehend all of the light members over his obsession with Thom Adcox, Miguel Ferrerr, Marina Sirtis and all the other voice actors he's worked with in the past since Gargoyles, he is to have the show include these villains where a few may replace those that the team subdues and these are the few he should consider acting as potential new members of the light and who he should cast to voice them
Nika Futterman or Cree Summer to voice Siobhan McDougal/Silver Banshee - New Member of the Light in the wake of Clarion's defeat by Siobhan Smythe (the Silver Banshee that is to join Nightwing's division of the team)
Robin Atkin Downes to voice Savitar - Dark Master of the Speedforce to Replace Black Manta as Member of the Light who in turned becomes second in command in his successor's place along with Savitar's Speedster Ninjas conjoining their alliance with his mercenaries
Xander Berklery to voice Prometheus - To serve as part of Ras' al Ghul's side of the Light
Now for Darkseid, with him in the show, Greg Weisman should consider having Tony Todd reprise his role from Lego Justice League or get Michael Dorn to voice him incase of schedule conflicts Next Are Darkseid's Elite who are yet to be cast while Tim Curry and Dee Bradley Baker reprise their roles as Godfrey and Desaad
Steve Blum to voice Kalibak (with the voice he provided for Killer Croc in the Batman Arkham Trilogy)
Tress MacNeille to voice Granny Goodness
Alan Rachins to voice Stephenwolff known for being Darkseid's Uncle and top General of the Parademons
Scott Cleverdon to voice Mantis
Rob Paulsen to voice Kanto
and now for some of the other villains that Weisman should introduce
Robert Englund to voice Scarecrow
Mark Hamill to voice the Penguin
David Ramsey to voice Killer Croc
John DiMaggio to reprise his role as Gorilla Grodd For one villain who shall be reformed later on
Joshua LeBar to voice Jason Todd/Red Hood - Who will be introduced in person into the third season starting off as a villain who assists Prometheus and the League of Shadows terminating most criminal threats in Gotham and antagonizes Batman for not perminantly ending Joker's rampage on the city and will also in this season should take on Nightwing and Silver Banshee (Siobhan Smythe) while fighting Batman inside the movie theater his parents were murdered outside in Crime Alley before joining Red Arrow and Cheshire who work outside the team since he is known for using lethal weapons and is not use to fighting crime through morality and doesn't care about criminals having equal rights as citizens because he sees that as the problem to why crime in Gotham never sleeps Now feel free to have Greg Weisman look at this article for some more characters he should include to make Young Justice Season 3 even more interesting