Out of all the bosses in Castlevania: Belmont’s Curse, only the Brittle King is truly optional. There is a tasty reward at the end of it in the form of Excalibur, the greatsword of Arthurian Legend and one of the most powerful weapons in the game, but that and the Brittle King’s Arcana powers are the only tangible rewards for this side endeavor.
And he doesn’t exactly make it easy to fight him in the first place. His chambers are in Notre Dame, close to one of the Sage’s Sigils, but as you enter the boss room, you’ll discover Excalibur wedged in stone with a plaque hinting at what you need to do to rip it out. Luckily, by this point in the metroidvania game, you should have everything you need to pass his test.
How to start The Brittle King boss fight
To start the Brittle King boss fight and pass his test, you only need to equip the Builder Arcana, gotten by defeating Talos in the Clock Tower. Once you do, simply use the sword, and the stained glass window behind you will speak. Eventually, it’ll get angry, mostly because nobody believes that he is King Arthur from the legends, and he’ll crash through.
