Starting the fight over control of the Lantern District (District Showdown) will become possible only after lowering D.U.P. control indicator to 30%. Head to the place marked on the map with a phone icon (large billboard on the roof) and make a call.
Shortly after you start the battle over the district in question, you should notice an enemy helicopter heading towards Delsin. Smoke category will prove very useful for taking down the enemy flying machine, since Cinder Missile attack (R1) from this category does not require prior charging. Switching to smoke is not absolutely required, and if you started with Neon category, you can stay with that (in this case, I recommend to often use close aiming in slow motion mode). In addition to the helicopter, you also have to get rid of the enemies occupying one of the most remote rooftops, and it would be good to approach them rather quickly, so they did not shoot at you any longer.
Rewards for taking control over Lantern District:
- Fast travel option
- Getting rid of all D.U.P. soldiers in the area
- A unique outfit for Delsin - Still Waters (you can change it in one of the menu windows opened by pressing Options button)