You have progressed through the Fields and have reached the Village Heart. This area may not have a ton of collectibles, but they are pretty well hidden. There are a total of six Rot Spirits you can find. Here are their locations.
Across the water
Once you reach the Village Heart, you will get a short cutscene showing that you are in the new area. Take the slides down and you will land in some water. Swim ahead and take out some enemies. Get in some more water and find a platform to stand on. To the right is a flower. Pull yourself over to it with an arrow and get ready to fire another arrow at a flower on a tree root straight ahead. This shot needs to be quick so you don’t hit the water. You will find a puddle to use Spirit Pulse on to get the Rot Spirit.
Top of the stone platforms
Progress through the Village Heart area until you reach the corrupted waters. Keep following the path and you will reach a large group of stones that you can make float. Make the stones float using your bombs and follow the path up to the next floor of the cave. You will see a long tunnel. Go to the left and the puddle containing the Rot Spirit will be on the ledge you just climbed up.
Obtaining the relic
Progress through the level like normal and eventually, you will come across the source of Adira’s Regret. After obtaining the relic, you will automatically be awarded three Rot Spirits for your efforts.
Under the elevator
Once you collect the previous Rot Spirits by gaining the new relic, don’t go up the elevator. Instead, head down into the water below and make a left. Go around to the underneath of the platform where the elevator is. There is a tunnel here. Further into the tunnel, you will find a platform with a chest and a Rot Spirit under a rock.