Suggestions by @stynis

Avril Lavigne

as Dusk in Scooby Doo and the Witch's Ghost

Score: +2

Victoria Justice

as Thorn in Scooby Doo and the Witch's Ghost

Score: +7

Ariel Winter

as Velma Dinkley in Scooby Doo and the Witch's Ghost

Score: +3

Katherine McNamara

as Daphne Blake in Scooby Doo and the Witch's Ghost

Score: +5

Dacre Montgomery

as Fred Jones in Scooby Doo and the Witch's Ghost

Score: +1

Charlie Rowe

as Shaggy Rogers in Scooby Doo and the Witch's Ghost

Score: +5

Frank Welker

as Scooby Doo in Scooby Doo and the Witch's Ghost

Score: +6

Indiana Massara

as Buttercup in The Powerpuff Girls

Score: +2

Emily Alyn Lind

as Bubbles in The Powerpuff Girls

Score: +5

Quinn McColgan

as Blossom in The Powerpuff Girls

Score: +2

Asher Angel

as Billy Batson in Batman and Superman: Public Enimies

Score: +3

Zachary Levi

as Shazam in Batman and Superman: Public Enimies

Score: +3

Tom Hardy

as Captain Atom in Batman and Superman: Public Enimies

Score: -4

Patrick Stewart

as Lex Luthor in Batman and Superman: Public Enimies

Score: -6

Robert Pattinson

as Bruce Wayne/Batman in Batman and Superman: Public Enimies

Score: +3

Henry Cavill

as Clark Kent/Superman in Batman and Superman: Public Enimies

Score: +6