Shikais

Shikais are a fictional species featured in the popular anime and manga series "Bleach." They are the spirits of deceased humans who have failed to reach the Soul Society, often due to lingering attachments or negative emotions in the mortal world. These spirits can become corrupted by hollows and transform into malevolent beings known as Hollows. Shikais are characterized by their skeletal appearance and the mask that covers part of their face, which varies in design depending on the individual spirit.

The progression from a spirit to a Hollow is a significant plot point within "Bleach." Initially, Shikais are depicted as relatively harmless spirits that Soul Reapers, spiritual entities tasked with guiding souls and battling evil spirits, would encounter. However, if a Shikai is exposed to overwhelming negative energy or is consumed by despair, it begins to decay and transform into a Hollow. This transformation involves the physical corruption of the spirit and a loss of its former identity, replaced by a primal hunger and a desire to consume other souls. The presence of Shikais and their potential for transformation into Hollows underscores the spiritual hierarchy and the dangers that exist in the afterlife as portrayed in "Bleach."