Suggestions by @simonzilla

Benedict Cumberbatch

as Keizer Ghidorah in SimonVerse: The Series

Score: +1

J.K. Simmons

as Storm King in SimonVerse: The Series

Score: +1

Eddie Murphy

as Rodan in SimonVerse: The Series

Score: +1

Seth Rogan

as Anguirus in SimonVerse: The Series

Score: +1

Steven Yeun

as Noah in SimonVerse: The Series

Score: +1

Lana Condor

as Ruby Gillman in SimonVerse: The Series

Score: -1

Denis Leary

as Earl in SimonVerse: The Series

Score: 0

Jack Black

as Simon in SimonVerse: The Series

Score: -1

Ben Kingsley

as Kratos in Simon x Ruby: Dawn of the Kaijus

Score: +2

Lacey Chabert

as Shimo in Simon x Ruby: Dawn of the Kaijus

Score: +2

John Oliver

as Baragon in Simon x Ruby: Dawn of the Kaijus

Score: +2

Gary Anthony Williams

as Dagon in Simon x Ruby: Dawn of the Kaijus

Score: +2

Mandy Moore

as Scylla in Simon x Ruby: Dawn of the Kaijus

Score: +2

Dodo (ARK: Survival Evolved)

as Chunky in Simon x Ruby: Dawn of the Kaijus

Score: +3

Toni Collette

as Agatha Gillman in Simon x Ruby: Dawn of the Kaijus

Score: +2

Ray Romano

as Behemoth in Simon x Ruby: Dawn of the Kaijus

Score: +2

Common

as Methuselah in Simon x Ruby: Dawn of the Kaijus

Score: +2

Patrick Warburton

as Gorosaurus in Simon x Ruby: Dawn of the Kaijus

Score: +2

Doug (MonsterVerse)

as Doug in Simon x Ruby: Dawn of the Kaijus

Score: +2

Brambleboar

as Brambleboars in Simon x Ruby: Dawn of the Kaijus

Score: +2