Second Breath

Name: Second Breath
Type of Rune: Chest
Type of Casting: Normal
Appearance: An anatomically accurate depiction of the heart and lungs lies concealed within an intricate pattern of overlapping images, most of men and women impaled by various weapons. The lungs seem to expand as the wearer breathes in and deflate as s/he breathes out, and the images of death seem more transparent the healthier the wearer is. As the wearer nears death, these depictions became extremely opaque and seem to cover his/her chest. When the rune is activated, the figures all seem to fall onto the lungs and heart, which then fade, appearing to be pushed into the wearer's chest.

Effect: The appearance when "cast" is as mentioned above, with the heart and lungs seeming to be pushed into the chest. The rune is activated by the wearer's total number of hit points in a topic dropping to or below zero. When the rune is activated, the wearer is instantly revived and gains a number of health points equal to the number of action points drained by the rune minus 50 or their maximum number of hit points, whichever is lower. Should the wearer have 50 or fewer AP at the time of activation, nothings happens. Note that a person can be reduced to negative hit points, so even if the wearer has 100 AP at the time of activation, s/he would still die if the hit would normally have brought him/her to -60 hit points or below.

Action Cost: When the rune is activated, it drains all of the wearer's AP remaining in the topic.
Memory Slots: 8

Patience Required: 80
Word Count to learn: 2500
Word Count to Inscribe: 1000

Might boost patience count a bit, but aside from that, I like it.

Edited up to 80, seem sufficient? I agree that it had been a bit low. Should I maybe even move it up to circa 100?

Looks good. I'll approve it (if that's necessary, but I don't know if you need two approvals since you're a mod yourself).
The patience could be boosted to 100, but since it also relies on having high endurance, I think it could be fine at 80.