Remark! This mission is recommended if you play as a hero and collect Good Karma. You should also know that beginning this mission blocks access to the mission 13b which is meant to be for a villain (Hunting the Hunters)
The starting point for this mission is right next to Eugene's hideout, in the Rainier district. Make sure, however, that you approach the correct marker, because the bad karma mission marker is right next to it. After you watch the cutscene of the meeting with Eugene, you will go towards the construction site, which is located in the North-Eastern part of the Lantern District. You will have to eliminate here a group of armed Akurans, who are staying inside the parking garage.
You can begin securing the parking lot from the roof or the cellar, however you like. You shouldn't have bigger problems with eliminating next gangsters because they don't have any superpowers. But be careful while facing bigger groups to avoid being under the massive fire. You can use this mission as a training ground for Video powers. But there are no interactive objects to regenerate it so you may have need to switch onto Smoke or Neon.
After clearing out the vicinity, start searching the areas where you're lead by the markers on the minimap (like on the screen above). Go through the big red Xs and listen to Delsin's comments. When you search all areas inside the parking lot, you'll have to get onto its roof.
Listen to what Eugene has to say. Now you know that your new plan is to jump onto containers with imprisoned terrorists which are attached to the transport helicopters of DUP. One of them is already flying over the construction site and you should focus on it. Get onto one of the highest shelve on the roof, wait for the helicopter to get closer and jump onto the container (of course, floating in the air is a good help).
After landing on the container, don't try to attack the helicopter as it'd have end in death of terrorists. Instead, aim at the shown on the screen catch and use basic distance attack (R2) to destroy it.
Now you have to detach remaining containers in the some way. They fly in the southern Seattle and their current position is shown on the world map. You can reach helicopters in the random order. Beware of enemies set up on the roofs next to the patrolling routes of helicopters. You can ignore or kill them (focus on the snipers). Use the Video or Neon powers to get onto roofs and then jump onto containers.
When you detach all containers, one of them should land in the Denny Park. Head there immediately, because big forces of DUP will appear there and they'll try to take over the terrorists. Good news is that you can count on support from angels and demons.
Make sure you're well prepared for a new battle (full health, lot of ammo etc) because there are many enemies with superpowers. First of all, aim for the elite enemies who look like scientists, because they are the biggest threat for Delsin. Also, when Delsin is seriously hurt or has no more energy, move away from the central part of the park to regenerate.
After some time, two elite agents of DUP will appear on the battlefield. They are similar to the boss from the eighth mission. You don't have to care about them too much, because game won't force you to eliminate them singlehanded. Avoid their attacks you already know (especially when they throw concrete at you) and eliminate weaker enemies. You have to defend until Eugene summons a huge angel. Only now help your allies in eliminating elite DUP agents (remember to hit directly them, not the flying around objects) and remaining enemies. This mission ends soon and unlocks a new one - The Return.