Spiritual Pressure (also referred as "Reiatsu") is the physical force/pressure that a person's Spiritual Power creates when released. Most Soul Reapers and Arrancars, even Quincy ans Humans (mostly Shinobi, Samurai, and a couple more) can manipulate the release of their spiritual pressure. The most powerful soul reapers that have a vast amount of Spiritual Energy, which they can emit in the form of Spiritual Pressure with devastating effects.
Spiritual Pressure (Reiatsu) VS Spiritual Power (Reiryoku)
The difference between spiritual pressure and spiritual energy (power) is simple: Reiryoku is the amount of energy a being has storedwithin their body and soul, whereas Reiatsu is the pressure that a person's spiritual energy (power) exerts. The difference is much like energy and power. Power being the amount of energy exerted per unit of time. Spiritual Power is potential while spiritual pressure is energy in use. In general, those with high levels of spirit energy will often have the highest levels of Spiritual Pressure also. A skilled warrior can overcome a person possessing greater Spirit Energy by possessing greater Spiritual Pressure.
Differents spirits have different colors of spiritual pressure, and it does not depend on the character's race or power: instead, the color is determined by the owner's personality.
- Blue: Sasuke Uchiha, Konohamaru Sarutobi, Sokomi Terumi,
- Light Blue: Suigetsu Hozuki,
- Light Green: Tsunaku Senju,
- Yellow: Gaara, Kumoto Uzumaki,
- Golden Yellow: Naruto Uzumaki,
- Red: Rasoki Senju, Onami,
- Pink: Karin,
- Brown: Uriwami,
- Orange: Jugo,
- Purple: Waken Terumi,
- Black with Red Outline:
- Black with Green Outline:
- Black with Orange Outline:
- Black with Purple Outline:
- Light Green with Dark Blue Outline: Tsuchiha,
Some particular characters have a shape or manifestation of their energy whenever they release enough of it. The manifestation are the one of the characters inner strength/energy.
- Ichigo Kurosaki: Light Blue Spirit energy in the shape of his Hollow Mask.
- Naruto Uzumaki: Yellow Spirit energy in the shape of the Nine-Tailed Fox
- Kenpachi Zaraki: Golden Spirit energy in the shape of a giant menacing skull
- Yachiru Kusajishi: Pink Spirit energy in the shape of a cat