Suggestions by @markclaunch

Tom Holland

as Sir Galahad in Once... The Second Book of Arthur

Score: +1

Maisie Williams

as Sister Elenne (Nun) in Once... The Second Book of Arthur

Score: +1

Joan Cusack

as Morgausa in Once... The Second Book of Arthur

Score: +1

Dacre Montgomery

as Sir Mordred in Once... The Second Book of Arthur

Score: +1

Liam Neeson

as King Gorlois in Once... The Second Book of Arthur

Score: +1

Tim Roth

as Sir Agravain in Once... The Second Book of Arthur

Score: +1

Christopher Eccleston

as King Anguish - King of the Fey in Once... The Second Book of Arthur

Score: +1

Helena Bonham Carter

as Queen of Fey in Once... The Second Book of Arthur

Score: +1

Lena Olin

as Queen Igraine in Once... The Second Book of Arthur

Score: +1

John Boyega

as Sir Hector in Once... The Second Book of Arthur

Score: +1

Sean Bean

as King Uther Pendragon in Once... The Second Book of Arthur

Score: +1

Ian McShane

as King Pelles (Fisher King) in Once... The Second Book of Arthur

Score: +1

Dave Bautista

as Sir Percial in Once... The Second Book of Arthur

Score: +1

Anya Taylor-Joy

as Nimue in Once... The Second Book of Arthur

Score: +1

Sean Bean

as King Pelles in Once... The Second Book of Arthur

Score: +1

Shawn Ashmore

as Sir Gawain in Once... The Second Book of Arthur

Score: +1

Aaron Ashmore

as Sir Tristian in Once... The Second Book of Arthur

Score: +1

Natalie Dormer

as Morgause in Once... The Second Book of Arthur

Score: +1

Henry Cavill

as Sir Lancelot in Once... The Second Book of Arthur

Score: +1

Peter Dinklage

as Sir Dagonet in Once... The Second Book of Arthur

Score: +1