The alien race known as the Khalashtar possessed the original psychic genome, and though their empire collapsed over a millennia ago the genetic code for their psychic power remained; passed on from race to race and generation to generation until the potential was brought to humans with the arrival of the Tabernacle and its mutation spores.
Psychic abilities can manifest in anyone, at anytime and for any reason. The Psions are iconic for the Galactic Accord, which is why many chaotically aligned groups do not trust them. One may be born a psychic but becoming a Psion takes training and focus, the privilege of which is only given after facing a heavy dose of sugar-coated Galactic Accord propaganda. The forces of Chaos saw that they needed a group of psychics of their own.
They came up with the Wilder.
The Wilder is spontaneous, uncontrollable and vicious. Where the Psion is balanced and muted the Wilder is explosive and unpredictable. The Wilder is a storm of emotions that can manifest in the real world and wreak havoc on anyone nearby. They are not evil, or particularly mean, but many Wilders became what they are today due to savage provocation and horrible brain experiments.
3rd Party Resources
Information on the Wilder class can be found in the 3rd party supplement “Psionics Unleashed” by Dreamscarred Press. I may do my own 3.5 conversions if I can find the time.
Wilders can be of any alignment, though most are Chaotic or Neutral.
Wilders have access to a new skill known as Autohypnosis. Psions use this skill for checks involving the mind, willpower and memory.
Skills (Knowledge: Psionics)
Wilders have access to a new skill known as Knowledge: Psionics. Wilders use this skill for checks involving psionic lore.
All Wilder’s can cast Augury 1/day using the Wlder’s level in place of the Cleric’s caster level. It should be noted, however, that unlike the Psion or the Loremaster, when the Wilder uses this ability she is communing with aliens that are not in league with the Galactic Accord yet which have an investment in Earth’s future.