That is a flagrantly absurd idea. In an age where realism (and "realism") is treated as sacrosanct and "darker and edgier" themes are still enjoying immense support, the inability to kill a mortal being that just-so-happens to be on the lower end of the age spectrum is going to stick out like the proverbial sore thumb. Program in (appropriate and reasonable) consequences. Hell, introduce an Alignment/karma meter. Whatever L does, it should be anything but that; having non-critical NPCs who would otherwise be susceptible to damage instead be inexplicably immortal is catastrophically immersion-breaking.
