The Cup is a puzzle item required for the Saber Expert puzzle in the First Sea progression. It serves as one of three key components needed to complete the puzzle, alongside the Torch and the Ancient Relic. Progress depends on collecting and using all three items together, making the Cup part of a set rather than a standalone item. Its value comes entirely from its role in unlocking and completing the Saber Expert puzzle sequence.

Obtainment:

The Cup is obtained in Desert, inside a house with a red door. To access it, the player must use the Torch to burn a brown curtain inside the house, which reveals a hidden room. Inside this secret room, the Cup can be collected along with a poem, confirming the puzzle-related nature of the location and linking it directly to the Saber Expert questline setup.
Usage:
The Cup is used as part of a progression step in the Saber Expert questline chain. When equipped, it can be filled with water by standing under a dripping stalactite inside the Ability Teacher’s cave. Once filled, the Cup of water is handed to the Sick Man, advancing the puzzle sequence and allowing progression toward the Rich Man’s quest, which is required to continue unlocking later steps of the Saber Expert puzzle.