With Part 2 hopefully completed (though not necessary to do Part 3), we can now snag the Jakotsu Mine Pearl and Warding Stone. For this guide, we will start by solving the Sacred Stone Puzzle first, which will give us access to the Ward. After this, we will find the Pearl and Warding Stone that needs to be placed in the Ward we unlocked.
To begin, you will have to teleport to the teleporter that is to the east of Maguu Kenki, which lies on the top of a cliff that overlooks Jakotsu Mine. Once there, glide down the hill and over the large pit, and you will find a Sacred Stone Mound. Rotate this mound to face east at the Tunderbearer Mirror next to a couple Electro-compass puzzles.
Now, you must go to the Thunderbearer mirror you aimed at, rotate it to face west, and angle it to aim downward. This should align it with the mirror just below it.
From here, aim this lower mirror northwest, at the mirror resting on the planks of the boney crag seen below.
Now at the boney crag mirror, aim directly south, and tilt this mirror down, so that it will strike the mirror seen below. This is the mirror roughly underneath the Sacred Stone Mound.
Now rotate this next mirror to face the east, at the Thunderbearer Mirror with a mirror floating just over it.
Almost done! Aim this Thunderbearer Mirror at the only mirror we haven’t adjusted yet. Do this by pointing this mirror northeast, so that it will redirect the shot across the mine.
And at last, aim the final mirror south and angle it down so that it redirects the shot into the large barrier (In the image below, the quest is complete, and the barrier has already been destroyed).
Now, once you strike the Sacred Stone Mound, a cutscene will trigger, and the large barrier around the Ward will be destroyed! With the Ward now available, you can investigate it and use elemental vision to find the Warding Stone and Pearl for Jakotsu Mine.
To get the Warding Stone, you will have to go left of the shrine and climb the rocks that lead to a cave. When you enter the cavern, you will find Thunder Sakura Boughs, and collecting their Electrograna will allow you to zap your way up the ledge shown in the image below. On this ledge, there is a small electro barrier that you can pass through so long as you have the Electrograna on you still. In this barrier, you will find the “Jakotsu Mine Rock Pillar Warding Stone.”
To get the Pearl, you will need to return to the Ward, and instead of left, head right (again, your elemental vision will also roughly guide you along this path). The Pearl will be through this branch of the cavern and require some combat, so be ready to fight primarily hydro enemies, both Slimes and Abyss Mages (one will be Electro). Eventually, you will come to the end of the cavern, as seen below. This is where the Abyss Mages will give you a hard time. Once you defeat them, use an Electrograna to access the Electro barrier and jump up to grab the “Jakotsu Mine Rock Pillar Pearl.” This one is in the air, so you may need to use a character with upward mobility like Venti, Geo Traveler, or Keqing. Perhaps you could even use the Wind Catcher gadget from Mondstadt.
With both the Warding Stone and the Pearl in your possession, return to the Ward and submit these two items to complete Part 3 of Orobashi’s Legacy.