Suggestions by @enzoooo

Rupert Grint

as Hermann Goring in Hitler: The Man, The Myth, The Legend

Score: -1

Beyoncé

as Benito Mussolini the Fat Entitled Italian Fuck in Hitler: The Man, The Myth, The Legend

Score: +1

Jim Carrey

as Adolf Hitler in Hitler: The Man, The Myth, The Legend

Score: 0

Sean Penn

as Emperor Palpatine in Star Wars

Score: -13

Laurence Fishburne

as Martin Luther King jr in Harriet

Score: 0

Dustin Hoffman

as Leonard Cohen in Hallelujah

Score: +2

Claudia Kim

as Yoko Ono in The Beatles Biopic

Score: -5