Suggestions by @the1b2

Miles Brown

as Beast Boy in Teen Titans

Score: 0

Vanessa Morgan

as Starfire in Teen Titans

Score: -1

Chandler Riggs

as Red Robin in Teen Titans

Score: -1

Millie Bobby Brown

as Raven in Teen Titans

Score: +3

Ron Perlman

as Nathan Summers in Characters Not Yet in the MCU

Score: 0

Alan Tudyk

as Annihilus in Characters Not Yet in the MCU

Score: +3

Nick Robinson

as Bobby Drake in Characters Not Yet in the MCU

Score: +1

Johnny Galecki

as Hank McCoy in Characters Not Yet in the MCU

Score: -1

Will Poulter

as Harry Osborn in Characters Not Yet in the MCU

Score: -2