Suggestions by @marrabasa

Pierce Brosnan

as "Lord Renoux" in The Mistborn Trilogy

David Harbour

as Breeze in The Mistborn Trilogy

Hugh Dancy

as The Lord Ruler in The Mistborn Trilogy

Trevor Stines

as Francis Abernathy in The Secret History

Callum Turner

as Henry Winter in The Secret History

Cameron Monaghan

as Arthur Weasley in All The Young Dudes

Emerald Fennell

as Molly Weasley in All The Young Dudes

Cody Fern

as Lucius Malfoy in All The Young Dudes

Nicola Coughlan

as Pomona Sprout in All The Young Dudes

Ashley Greene

as Madame Rolanda Hooch in All The Young Dudes

Rachel Weisz

as Minerva McGonagall in All The Young Dudes

Charlie Heaton

as Alastor Moody in All The Young Dudes

Saoirse Ronan

as Poppy Pomfrey (young) in All The Young Dudes

Jessica Sula

as Mary Macdonald in All The Young Dudes