Suggestions by @vadim_havard

Megalyn Echikunwoke

as Vixen in Flash

Grey Damon

as Mirror Master in Flash

David Corenswet

as Superman in Flash

Kumail Nanjiani

as Booster Gold in Flash

Peter Stormare

as Count Vertigo in Flash

Seth Gabel

as Count Vertigo in Flash

Matthew Kevin Anderson

as Clive Yorkin in Flash

Christopher James Baker

as Brain Wave in Flash

Tony Curran

as Despero in Flash

Hartley Sawyer

as Elongated Man in Flash

Jesse Reid

as Prankster in Flash

Neil Jackson

as Icicle in Flash

Darren Criss

as Music Meister in Flash

Peyton List

as Poison Ivy in Flash

Lane Davies

as Tempus in Flash

Isabela Merced

as Hawkgirl in Flash

Harry Lennix

as Martian Manhunter in Flash

Kayla Compton

as Allegra Garcia in Flash

Piper Curda

as Avery Ho in Flash

Stephen Amell

as Green Arrow in Flash