A nasty field of magic for anyone to engage in.
Magic of this field more often than not, have an unlimited range, last for years, and usually have no cool down, while also requiring very little mana.
This is only possible however through the expense of the user's own life force.
Each curse used by the user eats up a few years of their life. But rather than bringing them closer to the end of their life it brings them closer to the beginning.
Each curse performed by the user reverses their age by several years, the stronger the curse the more years that are taken. For a patient mage this can mean near immortality. For a reckless mage this could mean disappearing from existence with a few poorly placed spells
