ciao what is all this evil and demond stuff on the new game and how do te use it and can te use it for all the characters o just some of them?

What? The only ones who's had demonic powers were Akuma Ryu mostly, & it's been around since I think SF Alpha.

There are characters who can do some moves like Akuma o other dark powers but for fun, its not related to the strada, via Fighter story.