Location Ashen Slumber Black Myth Wukong

How do u get this transformation? Im having trouble looking up online so I thought I ask here
If there is any guide for it or if anyone can tell me short directions that d be helpful
 
Gotta defeeat the the Two Headed rats in the Yellow Rind village
Then u gotta head to a hut to talk to some rats
After which in the Pagoda Realm u gotta beat Captain Lotus-Vision

That unlocks some doors in the Lower Pagoda region
From the New West shrine, gotta travel along the cliff until u reach a room where u can pick up the spell off of a corpse