Bastion/The Hanging Gardens

Go down the stairs and proceed along the linear path. Eventually, you should spot a new character down below, and shortly afterward encounter enemies in the form of a pair of Security Turrets. These Turrets are of the flame-throwing variety, and while the flames do lasting damage, they lack range, so the attacks of these Turrets are easily avoided if the Kid keeps his distance and uses ranged weapons. Destroying the Turret blocking the path unlocks the gate behind it, allowing the Kid to proceed. The next area locks the Kid in between two gates with numerous Security Turrets, with only a sole Black Tonic to assist him. Take the hint and use whatever Secret Skill you have equipped to avoid taking too much damage from the crowd.

Past a green Gasfella, you should spot an unreachable memento. Proceed forward to form the path to reach this memento, called the Ura Sigil. Past this is a deck where many Fragments drop, but nothing else. Backtrack to take the other path forward, where a large Squirt spawns. Past this Squirt is another group of Gasfellas, which you should use your Secret Skill to deal with. In the center of the area guarded by these enemies is the Core. Pick it up to open the gate and speak to the Survivor to conclude the stage. Upon returning to the Bastion, speak to the Survivor about the mementos that you've acquired thus far.