Explanation for Chapter 9.
Okay, this was meant to be an A/N for chapter 9 but it would have been too long; instead I decided to put it in as a separate semi-chapter to avoid confusion. This will explain the background of the previous chapter, Dead Man Walking, and give some information that anyone who wishes to adopt the idea and write it up as a full story can refer to to understand how and why Naruto has his unsettling powers.
The actual story is crossed-over slightly with Warhammer 40,000; well done to those who knew that – Warhammer 40,000 (or 40K for short) is a tabletop game played with miniature models set in the grim darkness of the far future, the 41st millennium to be precise. This gothic universe has a massive realm of background information, but for brevity I'll try to stick with what a potential writer will need to know to make Naruto's powers make sense in the Naruto-verse. Note that, as I haven't played 40K in years, this is only my interpretation of the 40K background, so no flaming if you think I've got it wrong – it makes sense to me and that's all I'm saying.
One of the defining characteristics of 40K is the Warp. The best way to think of the Warp is as a shadow or mirror galaxy of our own, overlaid over the top of ours but completely intangible to most people. The Warp is constructed and contained by the collective emotions, or psyches, of all the inhabitants of the galaxy of the 41st millennium, humans being one such species. All humans have a very slight impression in the Warp, this impression being formed by the persons' soul, and can be characterised by these impressions; in terms of the Warp therefore, there are four classes of humans:
1) Average humans make up most of the population and leave a very faint trace in the Warp, little more than a candle flame in the darkness.
2) Some humans are more perceptive to the Warp and therefore have a brighter 'flame' in this place; the more powerful and open they are to the Warp, the brighter this flame will be. In our tangible universe, this perception usually manifests as psychic powers such as ESP, telepathy and the like, so these humans are called psykers. However, psykers for all their gifts are vulnerable to demons that live in the Warp, so most are tightly controlled by the governing bodies of the Human empire (the Imperium). About one in every ten or hundred thousand humans is a psyker.
3) Blanks are the opposite of psykers; these are humans who have souls but leave no impression in the Warp due to them possessing the Pariah gene. In the tangible universe blanks are often almost indistinguishable from normal people, but as their soul has no presence in the Warp (think of them as unlit candles there), they are immune to possession by Warp demons or psychic powers. Only about one in a billion humans is a blank.
4) The last and rarest group of humans are the people who can become a Culexus (plural Culexi?); only one in a billion, billion humans suffers this unhappy fate. Culexi are humans who are born without a soul; like blanks, this makes them immune to the Warp, but unlike blanks their presence there is as a small, moving void of utter vacuum. If a Culexus comes into contact with a normal person, their Warp-presence will begin to smother and dim the Warp-presence of the other person; in the tangible world this means most people tend to run away screaming from Culexi as their souls force them away from the sense of wrongness surrounding the Culexus. People who are forced to be close to Culexi quickly go insane or even die as the their Warp-flame is completely crushed and destroyed by the Culexus, leaving them as a lifeless, withered husk. People exposed fleetingly to Culexi, after getting away from them, rationalise their exposure as something else and forget, or force themselves to forget, their experience, making it impossible for Culexi to interact with anyone but another Culexus. Psykers, with the brightest Warp-flames, can't stand being even remotely close to Culexi as their presence cuts off their connection to the Warp, rendering their powers inert.
As you can hopefully see, Culexi in 40K are very rare, very frightening and very, very powerful; the Imperium trains Culexi for the sole purpose of assassinating enemy psykers and causing massive terror in enemy battle lines due to their unnatural presence forcing the enemy to get away from them regardless of orders or other such factors. To control their powers when not in battle, the Imperium has engineered damping equipment, the Animus Speculum, to mask the presence of a Culexus, though most people still can't stand to be in the same room as one.
As you have gathered from my story in Chapter 9, Naruto is now a Culexus; the battle between Minato and Madara forced Minato to accept that he had to kill, not just seal, Kyuubi to save the village not just now but in the future, in case Madara returned. To do this, he sacrificed his soul and the soul of Naruto as well as Kushina kept the bijuu busy with her chakra chains. Neither was expected to survive, but somehow Naruto did and exists as a Culexus, his soul being taken by the Shinigami. Needless to say, as a baby this wasn't too much of a problem as his 'vacuum' was very small, but the Sandaime and Jiraiya realised something was wrong and therefore set about fixing it as best they could.
The seal around Naruto's temple acts as the damper, like the Animus speculum, to mask his presence around normal people, though most instinctively still avoid him as their regular 'souls' recoil around the fact that he's not normal, and in fact could be lethal if he gets too close for too long. Jiraiya made this seal just a few days after Naruto was born and became a Culexus, modifying the Death God seal that was obviously never used by Minato. Jiraiya also made three necklaces with the same seal on it; when worn these fortify a normal persons' soul against Naruto's presence, allowing them to see him as a normal person. In Chapter 9, these necklaces are owned by the Sandaime, Jiraiya himself and Naruto's present teacher, either Anko or Iruka.
Note that Naruto still has chakra, as this is simply a mixture of physical and mental energy, both of which he possesses, so he can do ninja techniques; however as he doesn't have Kyuubi his chakra reserves aren't ridiculously massive. However his other gifts, as he explained to Anko, would make him an ideal assassin or spy; how can you defend against someone who your entire population recoils from and pretends they don't see?
Oh and as for his code-name, the books he was reading from the times before the elemental countries must have been an old copy of White Dwarf, the magazine dealing with 40K; he must have found the term there and carried it on. How did White Dwarf arrive in the Naruto world, and what do I mean by times before the elemental nations? Questions, questions for a future author to answer I think...
How this would be carried on, how he would grow and learn to further harness his gifts, being able to crush the souls of his adversaries, or direct his power against a target while leaving other people nearby less affected, I leave to you to try and write; I already have TMOK to deal with now and don't like to spread my focus too far. I hope this has been enlightening for you and gives you the information you'll need to take Dead Man Walking further.
Until next time then, ja ne!