How to Access the Secret Endgame Boss (Demon #127) in Bloodstained Ritual of the Night
After you complete Bloodstained Ritual of the Night, you may be wondering if there are any secrets left to unlock. To answer you question, yes there are. One secret you may not know about is a secret final boss fight. To help find it, here’s how to access the secret endgame boss.
Open the Good Ending Path
Before you can access the secret boss you need to first obtain the good ending of Bloodstained Ritual of the Night. This ending can be accessed by obtaining Zangetsu sword and then using on the Red Moon during the Gebel fight. Once you’ve done this a portal to new areas will open in the Garden of Silence.
The portal leads you to two new areas: Den of Behemoths and the Glacial Tomb. We need access to the Glacial Tomb to face the secret boss.
Explore At Least 99% of Map
The next thing you need to do is explore at least 99% of the map. Doing this unlocks a special book at O.D’s library in the Livre Ex Machina area. Once you reach 99% head to see O.D.
Check out Tome of Conquest from O.D.
When you speak to O.D. with the above criteria met, he will mention having a new arrival. This new book is called the Tome of Conquest. Take it out. With the book in hand head to the Glacial Tomb
Glacial Tomb Boss: O.D.
Once you have the Tome of Conquest on your person, make your way to the room marked above (first left room from Fast Travel). Here you will find O.D. waiting for you. He wants you to return the books you took, and he is gonna make you pay. This starts a boss battle with O.D.
What you Get For Beating O.D.
Defeating O.D. fills in #127 of the Demon’s List and unlocks the Standstill Shard for you to use. If you defeat O.D. and return to the library he will still be alive (vampire). Since you bested him you can check out as many books as a time as you want!
More: where to find demon #44.