Lost Key

With Death Perception obtained, head to the Normal version of the map and you'll need to look at every plant pot found around the map for an outline of a key. Once you've found the outline, you'll need to shoot that plant pot to break it, moving the key into another plant pot. You'll need to do this a total of five times, with the final plant pot dropping the key when broken.

If at any point, you break a plant pot that does not contain a key outline, you'll need to teleport to the Destroyed version of the map, and then back to the Normal version to reset.

Once you have obtained the lost key, head to the Green House Upstairs in the Normal version of the map, where you'll find a briefcase on the floor next to the bed that can now be opened with the lost key, containing your rewards.