Suggestions by @bradleysigma

Enver Gjokaj

as Goodman Grey in The Dresden Files

Score: +1

Enver Gjokaj

as Westley in The Princess Bride

Score: -12

Kenneth Branagh

as Gordon Edgley in Skulduggery Pleasant

Score: +8

Ciarán Hinds

as Auron Tenebrae in Skulduggery Pleasant

Score: +12

Aisling Franciosi

as Melancholia St Clair in Skulduggery Pleasant

Score: -6

Brendan Gleeson

as Kenspeckle Grouse in Skulduggery Pleasant

Score: +15

Kristian Nairn

as Mr. Bliss in Skulduggery Pleasant

Score: -5

Michael McElhatton

as Jaron Gallow in Skulduggery Pleasant

Score: +1

Andrew Scott

as Dusk in Skulduggery Pleasant

Score: +8

Aiden Gillen

as Artemis Fowl, Sr in Artemis Fowl

Score: 0

Colin Farrell

as Nefarian Serpine in Skulduggery Pleasant

Score: +23

Chris O'Dowd

as Vandameer Craven in Skulduggery Pleasant

Score: +2

Liam Cunningham

as Erskine Ravel in Skulduggery Pleasant

Score: 0

Aiden Gillen

as Solomon Wreath in Skulduggery Pleasant

Score: -1

Domhnall Gleeson

as Ghastly Bespoke in Skulduggery Pleasant

Score: -13

Nikolaj Coster-Waldau

as Verroq in The Bartimaeus Sequence

Score: +1

Tilda Swinton

as Raine Vinyáya in Artemis Fowl

Score: +1

Andy Samberg

as Chix Verbil in Artemis Fowl

Score: +2

Aubrey Plaza

as Opal Koboi in Artemis Fowl

Score: 0

Jesse Eisenberg

as Trouble Kelp in Artemis Fowl

Score: -1