The Key is a simple in-game item with no additional mechanics or functions described in the provided information. It serves as a basic collectible object, and its exact use or impact on gameplay is not specified in the available details.

Obtainment:

The Key can be obtained by talking to the Military Detective once the player reaches Lv. 700 or higher.

Usage:
The Key is a progression item used to unlock access to the Ice Admiral’s room, acting as a gate behind a locked area in the Frozen Village. It has no combat function on its own and exists mainly as a requirement to continue into the boss encounter tied to that location. Once obtained, the player travels to Frozen Village and enters the cave where the Ability Teacher is located. Inside, a large wooden door blocks the path forward, and the Key is used on this door to open the way to the Ice Admiral.