Suggestions by @chewchew

Randy Wayne

as Elongated Man in Justice League International (TV Series)

Miyako

as Doctor Light (Female) in Justice League International (TV Series)

Johnny Huang

as Ted Kord in Justice League International (TV Series)

Sean Gunn

as Maxwell Lord in Justice League International (TV Series)

Oded Fehr

as Ras' Al Ghuel in Red Robin

Billy Crudup

as Doctor Manhatten in Red Robin

Ben Schwartz

as Skeets in Red Robin

Austin Butler

as Booster Gold in Red Robin

Asher Angel

as Red Hood in Red Robin

Joe Locke

as Tim Drake in Red Robin

Chelsea Zhang

as Ravager in Red Tool

Oona O'Brien

as Punchline in Red Tool

Zachary Gordon

as Jericho in Red Tool

Jared Padalecki

as Edwin in Red Tool

Joaquin Phoenix

as The Joker in Red Tool

Margot Robbie

as Harley Quinn in Red Tool

Ryan Reynolds

as Red Tool in Red Tool

Aubrey Joseph

as Guardian in The Atom

Zekeria Ebrahimi

as Bart Allen in The Atom

James McArdle

as Felix Faust in The Atom