Shikigami conjuration is considered to be a type of cursed technique. Like barrier techniques, sorcerers who do not possess enough intrinsic talent for their own innate technique can summon simple shikigami.
Shikigami themselves are familiars incarnated by their summoners cursed energy. Summoning shikigami normally requires an intermediary, such as a common talisman. They are generally used to carry out an order in accordance with their conjurer's instructions, and they disappear when the user's technique is released or they are incapacitated.
Megumi Fushiguro possesses the Ten Shadows Technique, which allows him to collect and summon up to ten different shikigami using his shadows as an intermediary. However, the shikigami of the Ten Shadows Technique operate differently than a sorcerers simple shikigami.
Junpei Yoshino, a newly realized sorcerer was able to use a cursed technique that could summon shikigami with poison made from cursed energy, a skill Mahito claims would take other sorcerers years to learn.
Shikigami users are often thought of to be weaker at close range. Sukuna was surprised when Megumi, a fighter who employs shikigami, was comfortable fighting hand to hand. While training Yuji, Satoru advised him to always target the conjurer themselves should he fight a shikigami user. Noritoshi Kamo also mentioned to Megumi that a shikigami user who can hold his own in close combat is valuable.
An older curse user used shikigami to aid him in battle against Suguru Geto, who used the functionally similar Curse Manipulation. He also believed that shikigami users could be exploited in close combat.
One cursed technique imbued within Dagon's domain created man-eating fish shikigami would attack the user's targets with a guaranteed hit. Technique Release: Death Swarm is an endless stream of shikigami that instantly eats his targets alive.