Summoners are the most common type of guardian, though still rare in the clairvoyant community as a whole. They are able to call spirits from great distances simply by speaking their birth name. This is particularly useful when a violent or sympathetic spirit is required. The summoner may build up a cache of spirits upon which to call in times of crisis. This makes them a formidable threat in combat. Other clairvoyants can call spirits only when they are within reach of their aura. The greater the summoner, the greater the ability to assert control over the spirits that have been summoned.