Added 20 minutes later
I think I found a bug, take a look:
1) Follow the Demon path, i.e., obtain the Grail (Tear of Ashi).
2) Collect several pieces (I collected 10) to figure out the location.
3) Max out the Ashi's blessing in the luck branch.
4) Go to that location; it's a bit strange, and dig up the tear (I think the author understands how I dug up the tear).
And after all these actions, nothing happens. I went back to the demon, and he didn't say anything. Is this a bug? What should I do with the tear?