Suggestions by @untrustworthy

Kelly Macdonald

as Moira MacTaggart in X-Men

Justin Theroux

as D'ken Neramani in X-Men

Michael Shannon

as Bolivar Trask in X-Men

Jack Gleeson

as Mortimer Toynbee in X-Men

Louis Ozawa

as Kenuichio Harada in X-Men

Mido Hamada

as Amal Farouk in X-Men

Zach McGowan

as Victor Creed in X-Men

Nathalie Emmanuel

as Raven Darkholme in X-Men

Abbey Lee

as Cal'syee Neramani in X-Men

Eric Lange

as Karl Lykos in X-Men

Rami Malek

as Jason Wyngarde in X-Men

Hafþór Júlíus Björnsson

as Cain Marko in X-Men

Domhnall Gleeson

as Sean Cassidy in X-Men

Robert Sheehan

as Thomas Cassidy in X-Men

Mackenyu

as Shiro Yoshida in X-Men

Booboo Stewart

as John Proudstar in X-Men

Luke Benward

as Piotr Rasputin in X-Men

Jamie Campbell Bower

as Kurt Wagner in X-Men

Sophia Lillis

as Lorna Dane in X-Men

Milo Manheim

as Alex Summers in X-Men