Goku Black, usually referred to as Black, is the main antagonist of the Future Trunks Saga of Dragon Ball Super. His true identity is the original present Zamasu from the unaltered main timeline, in which he stole the body of the original present Goku and sought to destroy all mortals alongside Future Zamasu. He was given the name "Goku Black" by Future Bulma when he initially referred to himself as Son Goku.

This role might be taken by J's So Real, so first come first serve kind of thing, try to sound like Sean Schemmel, The Funimation dub actor, here's an example: https://www.youtube.com/watch?v=XEemerUghAI