The Gunslinger is like your standard ranged-attack unit, except that he really shines in indoor maps where there are lots of walls, because his shots ricochet off them. This also means you can attack units hiding behind cover, while being behind cover, provided you can find an angle that allows you to do so.
Again, I'm still using the placeholder 3d model, so they all look alike right now.
As usual, the work-in-progress, playable demo is available at http://anomalousunderdog.herobo.com/Unity/DZZPrototype.html
I made some dummy walls in order to demonstrate the Gunslinger's ricochet ability.