To help them cope with their immortality and often lonely existence, Spirits are driven to select one being they live alongside, referred to as their trusted. It can be considered the spirit equivalent of a soulmate. The relationship can be platonic, romantic, familial, or anything in-between, but the important thing is that the two trust each other without question and help each other through the challenges in their lives.

Once a spirit inevitably outlives their trusted, it is up to them whether to take another. Not everyone does.