Donut's self-harm compulsion spell, cited as the closest analogue to Li Na's Dark Purpose.
When Li Na describes Dark Purpose to the team, she says it is basically the same thing as Donut's Why Are You Hitting Yourself? — with the difference that the dread's feeling normally lasts only a moment, accelerating the longer someone is touching her.
Amplified through Tiatha's Wire Hack, the comparison stops being reassuring. Where Donut's spell turns a victim's own hands against them briefly, the broadcast dread has Mork pull out his own eyes and snap off a rib reaching for his heart, and a mantaur drive his blades through his own throat.
The familiar reference point that makes Dark Purpose sound survivable, right up until it isn't.
Also appears in books you've already read — spoiler-safe to their endings: