Suggestions by @cartoonmultiverse

Shockwave (Transformers Cinematic Universe)

as Shockwave in Tmnt: Golden Darkness (Part 1)

Starscream (TF Armada)

as Starscream in Tmnt: Golden Darkness (Part 1)

Arcee (Rise of the Beasts)

as Arcee in Tmnt: Golden Darkness (Part 1)

Iron Man (MCU)

as Tony Stark/Iron Man in Tmnt: Golden Darkness (Part 1)

Shadow the Hedgehog

as Shadow in Tmnt & Sonic: Null and Void

Deadshot (Injustice)

as Floyd Lawton/Deadshot in Tmnt & Sonic: Null and Void

Sonia the Hedgehog

as Sonia in Tmnt & Sonic: Null and Void

Killer Frost (AOA)

as Killer Forst in Tmnt & Sonic: Null and Void

Skye (Fortnite)

as Skye in Tmnt & Sonic: Null and Void

Leonardo (TMNT 2012)

as Leo in Tmnt & Sonic: Null and Void

Wolverine (Fox)

as Logan/Wolverine in Tmnt & Sonic: Null and Void

Steven Universe (Character)

as Steven Universe in Tmnt & Sonic: Null and Void

Fluttershy

as Fluttershy in Tmnt & Sonic: Null and Void

Brutus (Fortnite)

as Brutus in Tmnt & Sonic: Null and Void

Michelangelo (TMNT 2012)

as Mikey in Tmnt & Sonic: Null and Void

Batman (The Batman)

as Bruce Wayne/Batman in Tmnt & Sonic: Null and Void

Professor Charlies Xavier (James McAvoy)

as Charlies Xavier in Tmnt & Sonic: Null and Void

Raphael (TMNT 2012)

as Raph in Tmnt & Sonic: Null and Void

TNtina (Fortnite)

as TNTina in Tmnt & Sonic: Null and Void

Cyclops (Wolverine and X-Men)

as Scott Summers/Cyclops in Tmnt & Sonic: Null and Void