The third and final part of the Cleansing Defilement quest, players will have to destroy the barrier at the Kamisator Estate. This one is actually a lot faster than the others and less involved, but it certainly isn't easy at all.
First, players will need to get their hands on the key-shaped ward in order to purify the central lantern at the Kamisate estate barrier.
To start, players will need to head a little north of the Kamisato estate. Here, on a protruding spur of rock near the coast, they will find an earthen Kitsune statue that they can scan with the Memento Lens.
After scanning the Earth Kitsune and hitting the larger Kitsune that spawns with some Electro skills, the key-shaped Ward will appear. Players can then pick it up and head to Waverider's spawn area on the amp to the east.
After boarding the ship, players will want to head to the northeastern island. Here, right in the center and between three large Kitsune statues is another Earth Kitsune. Scan it again with the Memento Lens, then drop down into the hole that appears in the earth. Players will need to be sure to interact with the Sakura Thunder Boughs and get the elctrogranum buff for as long as they are here, as the environment will harm them if they don't.
Interact with the central lantern, using the Ward to purify it, then it's time to solve the puzzle. The first lantern will need a sign, just like all the other puzzles. The flags to the left and right of the first should have two signs each, and the front and back flags should have three signs each.
Interact with the main lantern again and two enemies will spawn. Yes, this fight is against two of Oschimusha's enemies. Eliminate them both to conclude this part of the search.