An ultra-thin, self-weaving net formed by nanobots, capable of slicing through metal, armor, and flesh. Attempts to move or break free result in severe lacerations. Target can still attack, defend etc., but they must remain in the same spot.
If the target moves, they take 3d10 damage. Teleports and similar does not count as a move, but being bull-rushed etc does.
For each 15 success rate, the target takes an extra 1d10 if they move. Concentration cost is increased by 1 per round you hold it.