Psionic energy is also known as mental energy, it is the energy derived from the thought and presence of a living being who is intelligent, self aware, and sentient. The energy produced is not energy in the conventional sense. That is, it is not energy that can be detected the way that light, heat, radiation, or other forms of conventional energy can be detected or manipulated. It is similar to Magical Energy and certainly related in some way (though the exact relation is unknown).
Every person has the ability to harness psionic energy from themselves, it takes skill and training to do so but it can be done. Unlike magic where some people just do not possess the ability to tap into magical forces directly. As with anything some people are gifted with vastly more potential and talent than others and the range of skill is a very wide space.
Source
Psionic energy comes from the mind itself but is unrelated to the physical brain or body. It exists separate from the physical world coming forth from the very consciousness of the person rather than the body. This is a kind of energy is personal and unlike magical energy it comes from inside. Depleting your own mental energy results in unconsciousness and it won't be replenished until the person sleeps and recovers it themselves. Usually this takes 6-8 hours, but can take longer.
Body and Mind
Since the body and mind are tied together, a person using psionic energy can draw more of it from the flesh of the body, essentially converting the natural strength a body has into mental energy. This can be a dangerous process, injuries develop on the body is too much strength is pulled away. Bruises are the most common but more serve injuries do occur.
General progression from least to worst cases (lowest energy used to highest).
- Bruising
- Burns
- Muscle Deterioration
- Bone Deterioration
- Death
Death is a very real possibility, the mind draws strength from the body to recover mental energy during sleep. If the mind and body are both depleted, neither will have a source of energy from which to recover.
Magic
Magical energy can be pulled from but those who have both the ability to use magic and Psionics are exceptionally rare.
Artifacts
Both the Solar Crystal and the Aurora Crystal can further be used as sources of psionic energy with a some difficulty even if the person does not possess the innate ability to use magic. Both crystals form a bond with their user which allows this to be done.