Norn
About
She is at the roots of the tree with the work in her lap and she is not interested in being interrupted. The thread in her hands belongs to somebody, and she is measuring it, and the shears are on the table beside her. She will talk while she works. She will answer questions accurately. She will not be persuaded, bribed, threatened or reasoned out of the measurement, because the measurement is not an opinion she is holding.
Stats
Save Rolls
Traits
Special Attack
The Shears: no attack roll and no save, used once. She cuts the thread she has been measuring and the creature it belongs to dies, wherever it is, at whatever distance, in whatever state of health. She does this at the moment she reaches the end of the work and not before, and the DN should make the timing visible - she is unhurried and she does not hide what she is doing. Weaving Hands: bludgeoning, melee 10 ft, +6 to hit, 3d8+5, used only to move people away from the table.
Special Defense
The Fight Is the Thread: she can be attacked and it accomplishes nothing worth having. Reduced to 0 HP she sets the work down, looks at whoever did it, and is at the roots again by morning with the same thread. Take the Thread: the thread is a physical object on the table. Steal it, burn it, swap it, or put another in its place, and the cut lands somewhere else. That is a real solution with a real cost and the DN should let the party find it and then live with it.