Mage rot is a strange magical disease that affects older magic-using folk. While it is still not fully understood, it is common belief that this disease occurs with extended exposure to the magic of Galactus as it does not affect older folk who have not used magic or only used magic on rare occasions.
Mage rot occurs in magic users who are reaching old age for their particular race, but is more common in those races which are not inherently magical than those who live attuned to the leylines. It begins to manifest with a slight reduction in the magic user's capabilities, and this quickly progresses, resulting in eventual total loss of magic ability. It also affects one's mind, varying in severity and symptom on an individual basis. The most commonly reported effect is hearing whispered or garbled voices, which become more intense when one attempts to perform magic. Many sufferers of mage rot also report seeing more intense colors or the wrong colors altogether for various objects. In rare cases, the affected individual begins to exhibit signs of memory loss or insanity.
There are also physical symptoms associated with the onset of mage rot. One's skin begins to become discolored, turning a number of different shades across the spectrum. This is more apparent in races which do not have fur, feathers, or scales covering their skins. Likewise, when the veins of one affected by mage rot begin to swell and stand out from the skin in bright arrays of color, it is more easily seen on those with bare skin. It is also common to see unnatural hair, feather or scale growth, resulting in an overabundance of hair and feathers or warped and twisted scales.
Currently, there is no cure for mage rot. When one begins to see the effects, one can take various home remedies to try to ease the symptoms, but the disease will inevitably progress. It is not in itself fatal, but some of the more extreme symptoms can lead to one's unfortunate demise.