Here are what I think the villains of the DC universe would be in the Crime Syndicate World, I am aware in the world of the CS in the Forever Evil book (not been following it) apparently there is no such thing as good or heroes but here are the heroes that could have been in the world and are known as the Justice Gang (their counterpart to the Injustice Gang), since Jokester and the Quizmaster exist I will be using them here:
Jokester: Jack Dent was the best cop on the Gotham Police Department, a loving husband and father who got disfigured in a fight with Owlman. He became the jokey vigilante known as the Jokester, loved by the media for being one of the biggest threats to the crime world of Gotham led by Owlman and the Jokester leads the Justice Gang along with Zod. He has a close relationship with his wife Harley and their daughter Duella.
Lex Luthor: the smartest man in the world and a businessman turned President of the United States. He is a very public supporter of the Justice Gang and even provides government funding for them.
Zod: General Dru Zod was the loyal leader of Krypton’s military and when he discovered the rogue scientist Jor Il attempted to take over the planet with a weapon he tried to stop him only to be trapped in the Phantom Zone. When he got out he discovered Krypton was now gone thanks to Jor Il’s weapon. When he came to Earth he discovered the Crime Syndicate led by the son of the man who destroyed his beloved home planet, he vowed to bring the House of Ill to justice for the planets they ruined. He has formed an alliance with the planet’s government and even helps lead the Justice Gang alongside the Jokester.
Quizmaster: Edward Nygma who is a police detective and was the partner of Jack Dent, he had a fondness for game shows and puzzles. When his partner became the Jokester he followed in his footsteps and became the puzzled themed vigilante the Quizmaster.
Sinestro: Thaal Sinestro a peaceful alien whose planet of Korugar was destroyed by Abin Sur using the Ring of Volthoom, seeking vengeance he found the Ring of Parallax, fuelled by the yellow energy of willpower he did battle with Sur until he came to Earth and gave his ring to Harold Jordan who became Power Ring. Teaming up with the heroes of Earth he now fights against the successor of the man who destroyed his homeworld.
Metallo: John Corben is President Luthor’s bodyguard became a cyborg powered by the one substance capable of harming Ultraman: Blue Kryptonite.
Slade Wilson: a military soldier who volunteered for an experiment to turn him into a super soldier to fight the Crime Syndicate.
Ventriloquist: Arnold Wesker is a popular children’s television presenter and ventriloquist whose most famous puppet is Mr Snoots. During a rehearsal the studio was invaded by mobsters but Arnold tripped over Crime Boss Gordon accidentally, allowing the police to capture him. The Jokester was impressed and offered Arnold a place in his empire of Gotham vigilantes. Arnold accepted and Mr Snoots became his sidekick and continued his television show, where his fellow heroes sometimes guest starred.
Penguin: Oswald Cobblepot a generous billionaire in Gotham who managed to subdue a gang of criminals who tried to take his club the Iceberg Lounge hostage, afterwards he decided he liked showing criminals whose boss and joined Jokester’s group of vigilantes.
Braniac: Zod’s persona A.I. and closest friend, through his android body he runs the Justice Gang’s headquarters.