Suggestions by @tylorwilliams

Shadow the Hedgehog (Sonic X)

as Shadow the Hedgehog in The Avengers

Score: +1

Shrek

as Shrek in The Avengers

Score: -2

Sonic the Hedgehog

as Sonic the Hedgehog in The Avengers

Score: +1

Dick Grayson (Robin/Nightwing)

as Dick Grayson/Nightwing in The Avengers

Score: +1

Steven Universe

as Steven Universe in The Avengers

Score: +1

Finn the Human

as Finn the Human in The Avengers

Score: +1

Ryuko Matoi

as Ryuko Matoi in The Avengers

Score: +1

Norville "Shaggy" Rogers

as Shaggy Rogers in The Avengers

Score: +1

Casey Jones (TMNT 2007)

as Casey Jones in The Avengers

Score: +1

Kim Possible

as Kim Possible in The Avengers

Score: +1

Max Tennyson

as Max Tennyson in The Avengers

Score: +1

The Joker (Animated)

as The Joker in Captain Nightwing: the First Avenger

Score: +1

Bruce Wayne (Animated)

as Bruce Wayne in Captain Nightwing: the First Avenger

Score: +1

Jason Todd (Red Hood)

as Jason Todd in Captain Nightwing: the First Avenger

Score: +2

Barbara Gordon

as Barbara Gordon in Captain Nightwing: the First Avenger

Score: +1

Dick Grayson (Robin/Nightwing)

as Dick Grayson/Nightwing in Captain Nightwing: the First Avenger

Score: +1

Shadow the Hedgehog

as Shadow the Hedgehog in Sonic

Score: +1

April O'Neil (2012 TV series)

as April O'Neil in Sonic

Score: +3

Princess Elise

as Princess Elise in Sonic

Score: +1

Princess Sally Acorn

as Princess Sally in Sonic

Score: +1