The Auric Spectrum, also known as the Auric Quartet, or simply as the Wave, refers to the two halves of Aura and Obscura, which are further delineated into Fighting!Aura and psychic powers for the former, and Dark and Ghost Obscura for the latter. Humans and Pokémon that use the power of the spectrum are calling upon the energy field that permeates all things in order to power their abilities, differing in what aspect of it they're calling upon.
Obtaining Auric Powers
Auric powers are normally genetic, with their wielders inheriting it through family members or through random mutation. The only other known way of getting Auric abilities is to have a mon form with Auric abilities such as the Riolu or Mienfoo lines, in which people can rarely keep their powers after being turned back.