A white-robed healer dragged a boy who was covered head to toe in arrows into the medical room. The stretcher was still dripping with his fresh blood. As the boy was laid on one of the beds, the sheets were dyed red. "Go bring some tweezers," the healer said to his assistant. "Make sure to get the small ones." The assistant cocked his head to the side. "Eugene used two types of arrows: sharp, which can be pulled out by hand, and dull, which caused our patient to use more life essence to defend, and after his life essence ran out, broke his bones. These shards can be put back together, but I need to move some around by hand to conserve my mana for the other contestants. It's a habit I picked up from my time on the front lines." The assistant nodded and hurried down one of the many hallways.
There is a series called Ajin that has immortals which regenerate after they die and they also get these things called IBMs which are black badass ghosts only other Ajins can hope to fight. One of my favorite parts of the series is how far they push the system and how many rules there are in those two simple lines.
Life essence enhances the body and one goes through many battles to get to a higher stage. I wonder how far I can push that statment?