There are three Will Seeds you can find in Kamoshida’s Palace in Persona 5: Royal. These locations are hidden, and if you locate all of them, you receive a reward for your dedication, which is the Crystal of Lust. If one of your party members equips this item, they gain the Diarama spell, which gives them a medium healing spell. It can later become the Ring of Lust if you give it to Jose in the Mementos.
To obtain the Crystal of Lust you need to find the red, blue, and green Will Seeds.
Red Will Seed
Thankfully, you cannot miss this Will Seed because it’s apart of the tutorial of introducing how they work. After you fight the Heavenly Punisher for the first time in the chapel, you will progress to where Morgana brings you attention to an ivy-covered door. You need to use your grapple to get across it, but when you do, you locate the red will seed.
Green Will Seed
The next will seed is after you reach the rooftop of the palace. Your party will remark how much closer you are to the Treasure’s location, and then three heavily guarded shadows are blocking your path in the courtyard. To get past them, you need to stick to the shadows and then use your grappling hook to swoop up above them. When you’re on the roof, jump across it to make it toward the tower.
You want to go until you reach the window opening taking you to the next portion of the area. However, instead of progressing forward, to the right of the window, you should see a small opening you crawl through. Crawl through, and you’ll be able to jump up several platforms. When you reach the one with a treasure chest, use your third eye to locate a grappling hook. Jump up there, and go through the next window to find the green will seed.
Blue Will Seed
The third and final will seed is closer to the end of the palace. Morgana will bring your attention to an elevator that has scantily clad women as pillars on either side of it. Go down the elevator, and you should enter a room blocked by a painting of Kamoshida. Run toward the art, and you’ll return to the central part of the castle. On the left side will be a small room you can enter that activates gears in the palace, allowing you to continue to the blue will seed room. You may want to use the save room on this left before returning.
Now, after activating those gears and saving, go back the way you came through the painting. Instead of going back up the elevator, take the left path, and go down. You now have a clear shot for the blue will seed, but there’s a fierce shadow in front of you that can’t ambush. You and your teammates will need to take it down. Hopefully, you saved.
When you have all three will seeds you should then obtain the Crystal of Lust, which you can give and equip to any of your party members.