Opening the boss door of the Ancient Cistern
The Blessed Idol serves as the Boss Key to Koloktos's chamber in the Ancient Cistern dungeon of Skyward Sword.
The key/idol resembles a meditating Buddha on one side and a half of a lotus flower on the other. The Buddha part of the key is inserted into the lock and the lotus side faces toward Link as he turns the key. The lock itself is designed to look like the Lotus, meaning that the lotus flower half of the idol connects with the lotus part of the lock, connecting seamlessly when the door is being opened. After the idol is used, Link is taken to the highest level of the Ancient Cistern, at the top of the dungeon's central Buddha's head, where he uses the Whip to activate mechanisms that raise the head and neck of the statue into the actual boss chamber. Here, Link once again encounters Ghirahim and ultimately fights the dungeon boss, Koloktos.
Skyward Sword does not use Boss Keys, and instead uses ornate objects that has to be rotated by Link to the correct position and then inserted into the lock before a boss battle. This is a prime example of the Motion control of the Wii being used perfectly as Nintendo set out to do in the concept and development of Skyward Sword.