Windmill of Time

The is a mysterious contraption that appears in Hanyō no Yashahime.

History
When Kirinmaru visits Sesshōmaru's mother, he was curious about the windmill in the sky near her palace. She has mentioned that she hasn't seen Akuru in such a long time, including that of Akuru's pinwheel.

After Zero have been struck by Setsuna's dormant Blood Blade, he observed from his ship that the Windmill of Time had finally began to turn if gradually.

Trivia

 * The Windmill of Time was first teased in BURN.