- For the Trinity-era usage of the word taint, to describe the power the Aberrants manifest, see Quantum.
Taint buildup within novas is common when novas over-extend their powers, or desire to learn a new power more quickly (i.e. getting an experience point discount).
Taint, throughout the Nova Age, is generally considered to be a bad thing due to the random physical and mental mutations it engenders. In truth, however, Taint is the key to a nova's evolution. Properly channeled (via the Chrysalis) a nova may avoid mental aberrations entirely. In exchange, they get more frequent physical aberrantions, but they may guide the development of these. A nova who sees himself as a representative of God, for example, might choose to become more physically perfect, and perhaps to manifest a glowing aura or halo, or even a set of wings.
However, such novas grow further and further away from baseline humanity, as their thought processes become more and more alien.
Although seemingly unknown in the Nova Age, by the Unity Age it's known that Taint affects not just novas, but their surroundings as well. This includes humans, plants and animals. In the environment, this can result in areas like the Blight. There are several places on Earth and Earth-space which display Taint to a greater or lesser degree.
When Taint builds up in a person the result is usually one of several different Taint diseases.