Radiance and Void are incompatible. One is energy, the other anti-energy. That doesn’t necessarily mean that one born of one cannot utilise the powers of the other.

This leads to what is often known as a “forbidden practice” due to it’s risks and dangers. Cross-spectrum casting.

CSC is the act of a being drawing upon, and manifesting or manipulating mana that belongs to the opposite spectrum they are born in. Living beings using powers of Void, or undead beings using powers of Radiance.

This practice allows beings of either spectrum to utilise magic and mana that is usually unavailable to them, at the risk of their health. Due to the nature of the two spectrums negating each other, CSC will intrinsically weaken oneself. Extended exposure will often lead to the snuffing of one’s internal strength and in turn, death.

Even in moderation, there are long term risks such as the permanent weakening of one’s inner strength, or afflictions to their body.