Hey! I like this!
Yes! Anything that allows you to use the Villians in Co-Op is awesome! The Fort Adventure proved this. For players that are stricly Co-Op only, this would give them some value for all of those skins on the Vilians side that NEVER GET USED.
Villians should be MERCS and should be able to be used in CO-Op Arena, plain and simple. If need be, make it so that you have to finish EVERY MAP on crushing to unlock the ability to use the Villians in Co-Op.
In adventure, after you have finished all maps on crushing and ulocked the Co-Op Star, you should then also unlock to ability to use other skins in Adventure. I know that set dialoge for the main characters scews this up a bit, but just nix the dialoge and let players run wild with Villian skins!
One time in my life NDI, and if not, get it straight in TLOU! One time!
Instead of Sark, Use mask sniper guy. When holding a sniper, enemies he points at will glow like it's call out. Helpful since I've had a lot of game where we run around looking for that one guy.
Never mind I forgot it already does show you what character you'll be in the loading screen.
Before the match starts though the game should tell you which character your going to be so your boosters and kickback can fit the character. I mean I think it's only fair to at least know what character you'll be.