Suggestions by @dippy2

James Franco

as Hunter Zolomon in Flash

Sam Raimi

as Director in Flash

Kirsten Dunst

as Iris West in Flash

Willem Dafoe

as Reverse Flash in Flash

Scott Speedman

as Flash in Flash

Lewis Pullman

as David Mazouz in Batman: Injustice

Giancarlo Esposito

as Wade Eiling in Batman 4: The Brave Knight

Liv Tyler

as Mera in Batman 4: The Brave Knight

Harrison Ford

as President Sam Lane in Batman 4: The Brave Knight

Carl Lumbly

as Lucius Fox in Batman 4: The Brave Knight

Jeff Trammell

as Director in Fastest Man Alive Flash

Colman Domingo

as Harrison Wells in Fastest Man Alive Flash

Jamie Foxx

as Weather Wizard in Flash No Way Home

Alfred Molina

as Gorilla Grodd in Flash No Way Home

Sam Claflin

as The Scarlet Speedster Flash (Flash 3) in Flash No Way Home

Scott Speedman

as The Fastest Man alive Flash (Flash 2) in Flash No Way Home

Willem Dafoe

as Reverse Flash in Flash No Way Home

Jacob Batalon

as Chester P. Runk in Flash No Way Home

Zendaya

as Ivy West Rusell in Flash No Way Home

Lewis Pullman

as Flash in Flash No Way Home