The future Hollow Ones are brought into contact with a Bound of immense power called the Tutor. Since its discovery around 1270, it is under close watch from the Seers (its prison is usually suspected in North Africa). The interaction leaves a gaping hole in the soul of the Sleeper, rendering him unable to ever Awaken and bleeds out their memories and personalities unless they are infused with Mana. As their minds are usually blank slates, it is easy for Seers to construct new personalities for them to infiltrate their enemies. Hollow Ones are traded among pylons for maximum utility.
- , p.217-218