ChainSpirits

In Arc, people tell stories about spirits. Most think that's all they are: stories. Those who share a bond with one know better.

The oldest stories say spirits used to be everywhere. Now you hardly ever see one. Ask around, and you'll mostly get shrugs.

You can't pick a spirit. The spirit picks you. And once it does, it stays with you and keeps you safe.

In Arc, a ChainSpirit is just called a spirit. They don't have names. They don't seem to need them.