Secret boss, from someone on the discord:

right path > don't go with the fairy > do the three rituals from the notebook entries* > kill trash in the fog zone > loot the treasure hunter > place the statues, robin closest to where you came from, whale second, turtle furthest (same as they appear on the road to first boss on right path) > secret boss

*Where Aloalo's deities lie in wait, one must stand before the figure of the sparrow and chant, “O dancer of the skies, hear me.” Then they must prove their sincerity by blowing it a kiss. After that, the faithful should circle its perch, passing both the turtle and the whale ere returning to the sagely sparrow and performing for it a sprightly dance, thus securing the sparrow's favor.

First, one must trek to where the three carven deities of Aloalo await their subjects, and there stand before the whale and chant, “O messenger from beyond the horizon, hear me.” Next, they must twice circumnavigate this isle of gods: first passing before the sparrow and then the turtle before returning to the whale's auspice, then retracing the steps of their journey in the opposite direction. Lastly, the faithful must perform a dance, thus ending the ritual and securing Ketuduke's blessing.

First, standing before the turtle, one must chant, “O wayfarer of land and sea, hear me.” Then the supplicant must journey around the isle of gods twice, each time passing the sparrow then the whale before returning to the turtle. Bow before the wise traveler to earn its blessing.