Ghost

A phantasm existence created by an Artifact, she moves according to her owner's will, despite her somewhat detached and reluctant persona. Because she is an existence similar to a phantom, concepts such as death, hunger or thirst are not relevant to her. She is able to replicate any ability her owner has, given their permission, and is capable of independent action. Any injuries to her in battle do not affect her owner, but on her death the owner will receive a certain degree of damage. While she can technically appear with any form and any personality that her owner wants, as Yoichi was still inexperienced with controlling her, she ended up looking very similar to him.