Nautilus

Original Form= The spirit of a submarine. She came along under the waves to check out the new island that had been formed by the undersea volcano. And, there, in a large sea trench near the volcano, she found a gate to the Other Side.

How to Acquire

 * "Ayakashi Quest" Event: Find and defeat her, and trade her for 500 Keys.
 * You can also obtain her Magatama for 100 Keys if you find Dora