Szeth didn’t know the mechanics, but it had been shared with him as he reached higher levels of training. A highspren could end their bond at any point, with no repercussions to either of them. No deadeyed highspren existed, or would exist. If Szeth walked away from his oaths, his spren would not be hurt. The way they did this involved a distance between them, which protected the highspren from the human. And that distance was part of why their attitude toward their Radiants was so different as well.

