Hide Life (Tome and Blood: A Guidebook to Wizards and Sorcerers)
Necromancy
Level: Sorcerer 9, Wizard 9,
Components: V, S, M, XP,
Casting Time: 1 day
Range: Personal
Target: You
Duration: Instantaneous (see text)
You isolate your life force in one single part of the body-typically the little finger on the left hand. You can then remove this part and store it in some safe place. Once the spell takes effect, you can no longer be killed by ordinary means: If damage or a spell effect would normally render you disabled, dying, or dead, you ignore the usual effects. Instead, you are staggered (only able to take partial actions).
While this spell is in effect, if you would otherwise be disabled or dying, you do not lose hit points for taking actions or having a negative hit point total. Healing does not automatically return you to 0 hit points but simply adjusts your current total upward.
If you would otherwise be dead, you cannot benefit from healing and simply fall down dead if the spell is ended.
If the hidden body part is ever destroyed, the spell is broken and your life force returns to your body if you would not otherwise be dead.
Material Component: A small sickle made of the purest silver, which you use to detach the body part to be stored.
XP Cost: 5,000 XP.
Ok, so you burn a 9th level Spell and 5,000XP one day and chop off your little finger, then for the rest of your unnatural life you're Staggered.
A couple days later you're hit with Finger of Death. It's ok, you can tank it.
Then an ubercharger Monk hits your face, repeatedly, for five million damage. It's ok, you can tank it.
Then the Warblade uses Time Stands Still and proceed to roll six Natural 20s in a row with his Vorpal Sword. It's ok, you can tank it.
They give up and run away, a couple days later a Mindflayer grapples and rips your brain out. It's ok, you can tank it.
A Wizard hears about your immorality, he shows up and sees your negative HP total and uses Power Word Kill. It's ok, you can tank it.
Then he casts Imprisonment, well you're screwed but you get the idea.
Anything that would outright kill you is ignored, including HP damage. Also, drowning your self is not a healing effect, you know in case you want to keep from going to far into the negatives. This also means you can have a Constitution Score of 0 which is pretty frackin hilarious. It also has the side effect of irrevocably winning against thousands of mundane builds for you. I'm sorry, did McFighter know how to kill me in 29 different ways by using his thumb? Sorry, I can't lose unless you use Flesh to Stone kthx.
...Which if you are turned to Stone and you're still immune to things that would kill you. Does that mean you are now an unbreakable statue? *ponders*