As Steppenwolf, Dance would certainly be augmented with digital effects, but that powerful voice of his would certainly give the character some serious authority.
As Tywin Lannister on Game of Thrones, Charles Dance was one of the most memorable characters on a series full of great ones.
Having said all that, what a great choice it would be if it happens to be true.
We know that he’s capable of playing the bad guy; Tywinn was one of the few characters for whom audience sympathies never seemed to shift, he was pretty much always a terrible person.