A skill named Unnatural Signet was available during some of the earlier Guild Wars beta events in 2004. At the time, spirits acted as irremovable global effects with long durations. Unnatural Signet would remove one spirit but had a 15s activation time, 75s recharge time, and disabled all the player's skills for 60-36s. When spirits were eventually changed into killable creatures as they are now, Unnatural Signet was removed. See  for an in-game description.