Fuels most of the world, seen as "spilling the world's blood"

Addictive, seen as a corruption that has to be endured to get to the "right" afterlife by the main religions. If not properly maintained by a good diet, using only what you need, or not using it entirely, it will slowly weaken a person's immune system and burn through stored energy.

seems to have a negative effect on signs of aging, at least.

will slowly consume a person's appearance depending on how long they've been exposed to it. hair will turn white, eyes become redder depending on the person's original eye colour.

Generally seen as one of the Elven's greatest assets, as its capacity for both healing and destruction were at its peak. It was an open secret, passed along through families, mentors, or society as a whole.

Taught through temples as part of the religion, magic corrupts the blood of the person who wields it, weakening their immune systems yet giving them more power and control over the world around them.