Alright here is how offensive decoy works. If you see a stationary group, eliminate as many as possible by using obstacles to block the compass. You will normally narrow it down to 2 people. Use decoy on one of them, if it is the player it will say you can only use it on civilians, and if it isnt well it will turn into a copy of you and you know the other guy is the real target. This could work with poison, but I wanted smoke for now to get focus kills.