Lingering Death

The Lingering Death is a lethal spell which kills an effected person over the course of several days.  The spell is very obscure, only mentioned in a few rare texts, and difficult to cast.  It requires several minutes to complete, and that time demands great concentration and the use of one's Focus.  The time and concentration make the spell unsuitable for combat or defense.  Because of this heavy disadvantage, and because of its obscurity and complexity, many mages simply do not bother with the Lingering Death even if they know (of) the spell.
The Lingering Death is, however, quite lethal.  Only two people have been known to survive the spell.  The first, known in the scientific literature as Patient A, was a soldier in the First World War.  While the spell was still in his ankles, however, Patient A was hit by a mortar which severed his legs below the knees.  The curse was quite literally cut off, and Patient A suffered no damage from the Lingering Death itself. An attempt to regrow one of his legs reactivated the Lingering Death, and the regeneration process was halted and the new growth amputated.  This kept the curse in check, and Patient A died of old age at 118.
Patient B was struck in late 2000 by Magio-Supremacist terrorists.  A mage with natural healing abilities was able to halt the progress of the Lingering Death and confine the spell to the victim's legs.  (It was later confirmed that this mage's healing ability was a product of ANMA).  Patient B is paralyzed from the top of the thighs downwards, but has suffered no other ill effects.

Effect

The Lingering Death kills all the nerves below the waist, including those that govern autonomic functions.  The kidneys and intestines cease to function, and the body slowly poisons itself.  Victims die painfully within a week.

Side/Secondary Effects

Because the Lingering Death kills all nerves below the waist, victims also suffer a lack of sensation below the waist and are paralyzed.

Manifestation

Victims feels intense pain over ten minutes as the nerves are slowly consumed.  Pain begins in the feet, travels up the legs, and eventually to the torso.  Victims have described the pain as a combination of electric shock and burning acid.

Discovery

The Lingering Death was discovered before the 16th century, as the first mention of the spell is in a 1515 commonplace book owned by a Talented noblewoman in southern Scotland.  (The name of the woman is not recorded in the book.)  The commonplace book mentions that the woman learned it from her grandmother.