Act 5: C3 - Free Parking
Start by taking cover, and hopefully you still have the longshot. Use it on one of the two snipers up high, then take out the other. Lots of drones on the ground, so snipe them, then on the sides will come flamer boomers, so take them out before they get close. Ammo up at the front of the building. Enter through the right side with Dom and kill the flamer and the drone who first meet you, then go up the stairs for two more enemies. Stay here and a Kantus and friends will make their way up to you. Kill the Kantus, then look over the side and pelt the enemies as they come up the steps. A grinder will emerge from the door below, and if you pump enough lancer ammo into his head as soon as he walks in, you should get him before he can do you real damage.
Frags and ammo, then go down the stairs. Take his mulcher outside. You don't have to start off with it, maybe press B and leave it in the middle walkway. Get on this center bastion and use it to take out the troika gunner, then the rest. Then comes a wave of maulers and wretches, so snipe the big guys to the left and right, then handle the little ones when they get close. Lastly is the hardest wave of two bloodmounts. You should use the mulcher here and take at least one out before it gets close, otherwise just use the lancer, not the longshot. Take them out and if one gets close you'll have to leap around or try to run away and hope Dom assists you.
Ammo near the entrance and on the left, then make your way to the other side and use the wheels to get through. The next area has a grinder and some drones on the right. You could go left and shoot them from afar. There are frags on this side and some ammo. After they are out, head past the wall and to the right is a newspaper in some leaves. Then go to the street and select the left path, the streets.
Dom should take out the guy in the building, then look to the left and shoot the tank on the wall to take out the guys in the building and make cover on the street. Snipe a few enemies, then move up to get the reaver to land, so take cover in the building and blindfire the thing. Snipe your way up and toward the middle you should see a second tank on the right to use as an explosive. Move up and Dom will help you clear the guys on the other side of this trench, and then Dom will meet up with you. He takes cover behind a barrier, so should you as a grinder busts though; just blindfire him.
Switch to your other gun besides the lancer and swap it out for the Hammer of Dawn on the ground. This gun requires you to aim, hold, and then the beam fires down. Use it on the two enemies up the road, then a reaver, then a mauler and some drones; you can lead the beam around as long as you are aiming, and the laser decides where the beam goes.
Go up to the corner of the street, and after the checkpoint, turn around and a cog tag is on the ground. Then just move up.