Mesha

Mesha (Ancient Egyptian, army) are a group of spiritually aware beings that either refused or did not get accepted into Shinigami training. As such, their power developed on it's own and, without proper training, became something else entirely. The difference between a Mesha and a Shinigami is as follows; First off, as a Mesha's power grows, it attempts to form a zanpakuto spirit. Since the Mesha cannot hear it, nor does he/she have the knowledge to control their reiatsu, their zanpakuto spirit morphs into a more monstrous form. The stronger the Mesha is, the more monstrous their spirit appears. Second, once a Mesha learns to control this spirit, it does not materialize as a sword, instead, the Mesha can summon the spirit to fight for him/her. Though there is a long process to gaining the power of this spirit. Incredibly powerful Mesha can generate up to three of these spirits. Mesha are also proficient in the use of Senzai spells.

Process
Once a Mesha's spirit, known as a Ba (Ancient Egyptian, spirit), has developed enough. They will put themselves in a trance and will spend three days attempting to materialize a Saew (Ancient Egyptian, guard) on their wrist. A saew takes the appearance of a regular golden wrist band, with a small square indention in the middle. At this point, the Mesha then uses a series of magical sealing spells, similar to kido to entrap their ba into the saew. Once Mesha can only store three ba in their saew and therefore, that is usually all they produce. It is common to only have one ba, however, extremely powerful Mesha can generate more.

Trivia

 * Mesha use the ancient Egyptian language to describe their powers.