{I need more voice actors; the more the better.}

Be able to express multiple emotions in a variety of different ways, like changes in tone and pitch. Be comfortable recording your voice and speaking with others. I would recommend that voice actors memorize their lines for their own benefit. Especially if you want to do more than voice acting; such as body acting.

If you are just wanting to do voice acting only then the requirement for having any required game is optional for you.