There’s quite a lot of process of elimination that can be done when narrowing down which Moon Knight villain Ethan Hawke will be playing.
According to The Hollywood Reporter, Ethan Hawke has been cast as a lead villain opposite Oscar Issac’s Marc Spector in the Marvel Studios Moon Knight Disney+ series. No details have been shared regarding the specific character Hawke will portray.
He almost definitely won’t be Bushmann considering that that villain is of African descent in the comics.
Hawke looks nothing like Oscar Issac, so he’s unlikely to be Randall Spector (Marc Spector’s mercenary brother in the comics).