Originally Posted by DChero
It's probably unrealistic, but since it looks like both Bats and Lex need an intro, I'd use the Slade Wilson from "Arrow" to add a physical threat to build up Batman, include the "Arrow" series into the universe and bring in a character that requires less screen time. His backstory can be abbreviated rather than as fleshed as the others should be.
Agreed. Deathstroke doesn't need any explanation at all. He's just a badass hired gun as far as BvsS is concerned. I think bringing in him from the show could be great.
I would also love it if Green Arrow made a surprise cameo.
(Perhaps Batman defeats Superman with the help of Green Arrow from afar, another nod to Dark Knight Returns. I think that could be an awesome moment.)
And although I think the actors for these two would fit in just fine, it doesn't necessarily have to be the same continuity/actors.