Suggestions by @vince

Nikolaj Coster-Waldau

as Lockhart in Harry Potter

Score: +1

Rory McCann

as Hagrid in Harry Potter

Score: +1

Iwan Rheon

as Wormtail in Harry Potter

Score: +1

Aidan Gillen

as Barty Crouch Jr in Harry Potter

Score: -1

Woody Harrelson

as Voldemort in Harry Potter

Score: -1

Aaron Eckhart

as Xenophilius Lovegood in Harry Potter

Score: +1

Tilda Swinton

as Bellatrix in Harry Potter

Score: 0

Alexandra Daddario

as Tonks in Harry Potter

Score: +1

Cillian Murphy

as Snape in Harry Potter

Score: +2

Anthony Hopkins

as Dumbledore in Harry Potter

Score: +1

Sadie Sink

as Ginny Weasley in Harry Potter

Score: 0

Mads Mikkelsen

as Lucius Malfoy in Harry Potter

Score: +4

Cate Blanchett

as The White Queen in The Chronicles of Narnia

Score: +3

Timothy Spall

as Mayor Lipp in The Ballad of Songbirds and Snakes

Score: +14

Jamie Campbell Bower

as Coriolanus Snow in The Ballad of Songbirds and Snakes

Score: -65

Jessica Henwick

as Clemensia Dovecote in The Ballad of Songbirds and Snakes

Score: -11

Lulu Wilson

as Lamina in The Ballad of Songbirds and Snakes

Score: +3

Hugh Laurie

as Dean Casca Highbottom in The Ballad of Songbirds and Snakes

Score: +7