Phase matter is a unique type of anomalous material that can be found composing many unique, ghostly organisms. Scientifically, it is called quasi-neutric matter. Phase matter is a material that is seemingly intangible, reacting almost very little with matter to the point of making it one of the softest materials known; it is a strange feeling of holding it, as the phase matter will partially sink into your skin and cause a tingling sensation due to the electrons present sparsely in the material; phase matter can even be 'forced' into other matter due to its limited interaction with physical matter in its inactive state, and can generally appear in many different forms much like normal matter. What phase matter actually is, however, is much stranger; phase matter is matter that is quasi-neutrinic, essentially normal atoms instead mixed in a sea of neutrinos that counteract the electromagnetic force outside the matter save for sparse electrons. When phase matter is energized even slightly, it holds a disregard for tangibility and passes through matter and floats through space, with seemingly no mass at all; this is caused by repelling electrons out the matter, causing it to take on a 'soft' and transparent appearance. During this state, phase matter cannot be reacted with physically at all save for some few options such as radiation or other immense energy, making it an absolute mystery to behold for primitive species that cannot explain its phenomenons.
Many classifications of organisms use phase matter as a major part of their biological make-up, having ghost-like appearances. Many of these organisms can be found in a variety of places, though many more can be found in places with a higher ECF (environmental cuil factor) suitable for more anomalous species. Examples of these organisms include Qarins, Wispers, Erchius Ghosts, and many more. The biology of these organisms can be complex, but despite being made of phase matter, they are still somewhat similar to our own - phase matter organisms still have organs just as we do, such as eyeballs and central nervous systems. They also require a source of energy, such as absorbing latent heat or radiation from their environment, sapping the bioelectricity of other organisms, or enveloping food in digestive tissue that allows it to be broken down into energy. In addition, phase matter organisms require some means of locomotion; many high-density organisms simply project ions in order to propel themselves.
Phase matter has a lot of different properties that organisms made of it can take advantage of - one such property is its neutric density, which is its density of coupled neutrinos which determines how much the phase matter is able to physically interact with other matter. Some organisms have such a high neutric density that they are able to completely pass through walls save for thick lead or plasma barriers, whereas some organisms can even change their neutric densities in order to become more or less tangible. One example of a common phase matter organism that does this is the Qarin, which can lower its neutric density to such a degree that it can become nearly completely solid. The less dense phase matter is, the more mass it has, and phase matter with a very high density can even be completely invisible to the naked eye, detectable only via special instruments through touch only. Another property of phase matter is that it is analogous to normal matter, just simply coupled with neutrinos. This means that there can be different materials of phase matter, and even elemental metals such as iron or alloys like steel can become neutric, taking on more of their analog’s properties the less their neutric density is. For example, if a Qarin has a sword made of steel, when that Qarin is manifested, that sword is actually steel, and can cut things like it was made of steel.
Aside from its varying levels of neutric density that changes its tangibility and mass, and its nature as an analog to ordinary matter, phase matter has some other properties. The electron and neutrino matrix composing phase matter is disrupted easily by plasma or intense heat, making plasma and laser weaponry very effective weapons against phase matter organisms - this weakness becomes less of an issue the lower the phase matter’s neutric density. Phase matter can also interact with other phase matter as if they were real matter, depending on their neutric density - if they have the same density, they can interact as normal, but a lower density phase matter would not be able to interact with a higher density phase matter as much. Finally, as an anomalous material, the stability of phase matter changes depending on the cuils it is subjected to - the less neutric density phase matter has, the more stable it is when not in its normal cuil level, whereas phase matter with a higher neutric density often requires higher cuils to remain stable. Some organisms such as Qarin become stronger when they are in higher cuils. In addition, phase matter will naturally ‘evaporate’ or decay when not sustained by any organism. This decay process is faster the lower the cuils it is in are - the products of this decay seem to be the ordinary analogs of the phase matter, usually elemental, and trace amounts of a strange black powder.