4th Floor

Head north from your starting point, collecting the map chest. Proceed through the door, being mindful of the two Watchers.

At the first dead end, you'll find a one-way shortcut leading back to the start. Continue north.

In the southeast corner before the next door, there's a one-way shortcut to a small room containing the armor Emery Meisen. Be aware that The Reaper will begin chasing you here; enter, grab the chest, and immediately exit via the other one-way shortcut.

Return to the previous room and take the western door.

Proceed north to find a chest containing Chaos Robes. Continue to the next door, which leads to a dead end event and a Power Spot.

Take the southern door. You will enter an area where The Reaper will chase you from the right.

Observe the two pistons: the right one should be up, and the left one down (if you came directly from the third floor). Your objective is to reach the southeast portion of this area to find stairs leading back down to the third floor.

Once on the third floor, open the shortcut near the first piston you encountered.

Back in the southern section of the fourth floor, go north along the conveyor belts to find a chest with Quartz Mail.

Return south slightly and activate the button to raise the second piston. This will allow passage past The Reaper on the floor above. Return to the fourth floor via the stairs.

On the fourth floor, the right piston on the third floor should now be down, and the left piston on the fourth floor should be up. Lure The Reaper to the west side of the western piston. This maneuver will allow you to bypass The Reaper and reach the stairs to the fifth floor. Open the shortcut located near these stairs.