Psi or "Psionics" are a type of supernatural power. They include telepathy, telekinesis, and the ability to manipulate matter and body chemistry through mental prowess. Some of these abilities extend to mental suggestion and crude forms of mind control.
Psionic abilities manifest themselves innately in some individuals just the way Magicke does. Very few are born with the ability to manipulate psionics. Telltale signs of psionic adepts are the ability to use limited telepathy in the form of "empathy", a property that allows the user to sense the emotions of other beings. Often, this ability can be trained into proper telepathic communication.
Though children born with these abilities are exceedingly rare (Read: fuckin' rare), Draconic races seem to have a higher number of adepts born among their numbers. As a result, in draconic kingdoms, psionics are better understood, and more widely used.
There are extremely rare cases of individuals gaining psionic sensitivity from psionic encounters with other adepts and users. Rarer still, from traumatic events that appear to "unlock" innate psionic abilities possessed by "mundanes". It is impossible to train anyone to use psionics if they are not born with these innate abilities.
Returners gain Psionic abilities when they are infected with the Jiangshi virus. They have their own specialized school and various Academies that is unique to their underground culture. This School of Psionics differs from the one used by Draconic and Furre kingdoms.
Psionics can also be used to control the functions of the body. A common application of this is the regulation of body temperature, heart rate, and the resistance to poisons and injury through meditation. This is a trained skill.
Furthermore, some Psi users can influence the minds of others through concentration and highly developed abilities. This would require their intended targets be distracted, or for any reason lacking in the will power to overcome these telepathic suggestions.
Some Psi users have actually developed the ability to move and sometimes even destroy objects with their power. This involves creating a psionic "field" around physical matter and moving or levitating the field with the object contained inside it. This can cause considerable mental drain on the part of the user.
Many psionic adepts succumb to the destructive effects of their powers, and are known to go insane or be institutionalized while pursuing the full spectrum of their powers. For this reason, many nations remand psionic children into the care of a very small number of psionic academies, ostensibly for their own safety.