Canon:Nameless One

The main character of Planescape: Torment is a nameless human with a unique form of immortality. Rather than being protected from injury, his specific brand of unending life allows him to raise from the dead due to regeneration abilities, like a troll. However, with each rising, he loses large chunks of his memory, leaving him little clue as to what he was doing or even where he is.

To counter this disorientation, the Nameless One had important facts tattooed on his back in large runes. These become hard to read, as the other side-effect of this immortality is to always bear the scars of combat. By the time of the opening of Planescape: Torment, the Nameless One is heavily scarred, a testament to how many times he has "died."