There are four “rats” here, small, annoying and dangerous goblin-like enemies that’s worth 90+ EXP each. They also have the chance to drop Gachiin’s Sugar, a consumable that suppresses sound and presence temporarily. You can quickly and easily dispatch them with a strict, methodical approach as discussed below. This farming spot is also near the Shugendo Memorial Mob merchant.
Here’s the rundown of the farming method but feel free to apply your own strategy or enemy priority.
From the sculptor’s idol, grapple to the nearest branch then grapple to the next point at the edge of the cavern below. Continue to the tunnel and carefully walk towards the other end but don’t exit yet. If you move near the statue as shown below, you can trigger the enemy on the upper-left ledge to turn around and drop down where you can easily backstab it.
From there, grapple to the other cliff and take out the next enemy.
Next, look back to the main path and grapple to the next point. This will take you directly behind another enemy. Backstab it.
After that, walk to the wooden walkway and around the corner. Stop, then double-jump on the rock wall as shown in the image below then grapple to the next branch to the left. This will allow you to reach the branch without being seen by the last enemy guarding the wooden pathway.
From that branch, look down and lock on the enemy below. Jump and perform an aerial deathblow to complete this farming run.
Since the sculptor’s idol is nearby, just turn around and jump towards the first branch you grappled and you’ll reach the idol in a few seconds. Rest there and repeat.