If Pokémon Talked: Generation II
Austin E for Quilava/Typhlosion (Male)
Quilava is the evolved form of Cyndaquil. It has more of a burning passion for battle than it's previous evolution. It will also intimidate its foes with its flames. I would imagine Quilava having a young energetic teenage voice. I may have listed young adult for this, but I would recommend more of a teenage voice coming from this Pokémon.
Typhlosion is Cyndaquil's final evolution. Once its rage intensifies, anything that touches this Pokémon gets burned to a crisp. It also hides a secret move that can cause gigantic explosions. With this Pokémon's voice, it would have more of an adult voice and I would consider it having the type of voice that makes it sound ill-tempered and always prepared for a battle. This role will also contain a bit of screaming.
Quilava: I am on fire. But I don't get burned. Fire is my specialty!
Typhlosion: Anything that comes near me gets burned to a crisp. You've been warned, newcomer.
I thought the Quilava was good, but the Typhlosion was off. I'm sorry I let you know a bit too late, but there's chance you could be cast in another role you tried out for.
No worries. I completely understand. Thanks for the feedback. I really do appreciate it. Have a good day and best of luck on the project. :)