- The Original Darrin: Optimus and Rodimus Prime are both voiced by their G1 actors instead of the actors from Combiner Wars
- The Other Darrin: Likely due to the backlash of having mostly internet/YouTube personalities in the voice cast, roughly half the cast was changed between this and Combiner Wars, for better or worse:
- Optimus Prime*
- Role Reprise:
- Peter Cullen and Judd Nelson return to voice Optimus Prime and Hot Rod respectively.
- Victor Caroli, narrator of the original cartoon and movie, returns to recap the events of the previous series.
Trivia / The Transformers: Titans Return