The Moon-Bathed Deep is a world quest available in Watatsumi Island.
Your objective is to break the five seals on Watatsumi Island to enter Enkanomiya.
Here’s a walkthrough and guide of The Moon-Bathed Deep in Genshin Impact.
This guide is divided into various sub-quests.
To begin the quest, go to Mouun Shrine on Watatsumi Island.
You will see an NPC called Tsuyuko. Talk to her to begin.
Tail of Watatsumi
The first one is the Tail of Watatsumi. The island is just near Tsuyuko, as marked on the map below.
Glide towards the island.
Read the ancient stone tablet near the shrine. They will say that there are 3 spots to look at, i.e. north, south and west.
Head to the south of the island and use your elemental sight. You’ll see a purple orb. Destroy the orb with an elemental skill and some mobs will spawn.
Head south and you’ll see another orb near two Ruin Sentinels. Defeat the sentinels.
Now, head west and climb up the hill. Jump down a little from the peak and you’ll see the orb.
Finally, head back to the shrine to obtain the spirit pearl.
Fang of Watatsumi
The location of the fang is marked on the map below.
Like before, go to the shrine and read the stone tablet.
This one is basically to protect the Ley Line Monolith. Start the challenge when you’re ready.
You will face a few waves of monsters. Keep defeating them to reduce the time left. Once the time is up, your job is done.
Get the spirit pearl.
Fin of Watatsumi
Next one is Fin of Watatsumi and the location is marked below.
Read the stone tablet again.
This one requires you to break the “Fin” seal. There are two circular areas where you have to align the statues.
You basically need to face the statues towards the middle and you’ll see the blue lines forming.
Once the middle is lit, you see water bubbles coming up. Remember to interact with the fourth statue which looks like a shell. This will keep them in position when you adjust the statues on the other circle.
Do the same thing for the other circular area.
Obtain the spirit pearl once the seal is broken.
Tail of Watatsumi
The fourth one is the tail and it’s located at the southern part of the island.
As you reach the area, defeat the Fatui members.
Now, head to the electrograna and summon one. Walk towards the unique-looking stone structures and they will light up from the electrograna.
There are around six of these stone structures.
More Fatui members will appear. Defeat them first.
Take the spirit pearl when you’re done.
Heart of Watatsumi
After obtaining four of the pearls, head back to Sangonomiya Shrine.
Talk to Tsuyuko who is at the shrine.
Then, head east to the marked location.
Jump from the top and you’ll see the marked spot. It’s to open the gate to the Heart of Watatsumi.
Give all four spirit pearls to open the gate.
You will now see four of the circular mechanisms like the ones you found earlier.
The objective is the same. Align all of the statues and make them face the middle of its own circle.
Once they’re aligned, some water creatures will spawn. Take them out first.
Then, remember to interact with the pearl statue. This will stop them from moving when you adjust other statues on other circles.
Do the same thing for all four circles. The creatures will spawn in each circle as well.
Once you’ve adjusted all four circles, more water creatures will spawn.
There will be a few waves of them.
After defeating them all, the seal will be broken.
Obtain the Key of the Deep from the middle of the area. Talk to Tsuyuko and you’re done for now.