Of course, Oliver Queen knows who Damien Darhk is courtesy of having met the no-good Darhk whilst Ollie was under his Green Arrow guise, but in Darhk's mind Oliver and the Emerald Archer are two different people still at this stage of the game. As such, Darhk thinks nothing of threatening Oliver as he makes his run for Mayor of Star City. Its fair to say that Ollie doesnt let Darhks intimidation get to him, instead focussing his attention on doing what is best for Star City. Then Darhk strikes. Hard. Sending a drone to unleash rounds of fire on a shoreline of kids. Not cool, Damien. Not cool at all. The big surprise here, though, is that rather than go after Darhk as the Green Arrow, Oliver takes to the local news station and publicly reveals what Damien is really up to and calls him out. Its a ballsy, some would say stupid, move and one that certainly came as a bit of a shock to many, including some of Team Arrow who maybe thought publicly naming and lambasting this super-powerful bad guy isnt necessarily the greatest of ideas.