WTF IS THIS?

So I recently went on CA after a long break cause my friend wanted to play and I said why not. First thing I noticed that there was some kind of grenade launcher that shot a gas that made your screen flash blue just like incendiary nades make it red, and inverted your aim. WHAT THE FUCK IS THAT? That is so stupid! Dunno what it's called, but I think it's ridiculously overpowered...

I dont think it is a launcher but it is annoying unless your like me a pro invert player.

I think it's one of the new assassin's weapons.