The Death Note only works on names that people consider theirs. A true name can be a person’s birth name, a married name, a name that they changed legally or illegally (via fake IDs), or any other name as long as it is one they feel is connected to their sense of self and identity. So dead names can’t be used to kill trans people, a person who changed their name, or anyone else who doesn’t consider the written name to be theirs.
Since the Death Note cannot directly affect anyone other than the individual(s) written down, it can’t be used to murder pregnant women. They are immune like babies are.
There are others who are immune. People who are deemed vital (such as a scientist who will invent a cure for a rare condition) by a higher power can’t die until their original fated time.
Fate can be changed by actions. It is usually NOT set in stone. The average person’s lifespan is constantly fluctuating because of their choices. People can also die before their time via murder, car accidents, suicide, etc.
Shinigami and people with shinigami vision can see the fluctuations. If they see a person’s lifespan suddenly plummet downward, that is an indication that the person might be murdered, get into an accident, commit suicide, or die through any other unexpected event. If the lifespan spikes back up, the danger did not occur.
Shinigami are known by other terms around the world. They can be referred to as reapers, angels of death, and many other names. When in a specific area of the human world, they typically go by whatever term the locals call them.
While shinigami can’t breed at all, certain high-ranking ones (like Nu and the Shinigami King) can bestow humans with power. This can be because the human is worthy or because the shinigami was curious, bored, or spiteful. As I mentioned in the L and Wammy headcanons post, that is how BB got shinigami vision. Nu was curious to see what would happen if she gave the vision to a baby and she did not enjoy the result. She felt bad for doing it to B.
Shinigami can write a dying person’s name down or just let the death happen naturally. It doesn’t change much unless the person is dying in a painful way (like wasting away from a terrible disease) and having their name written would be a mercy instead.
Shinigami are forbidden from killing anyone who is not fated or that they did not make a contract with. If they do murder someone, they will be punished. The punishment isn’t death unless they’ve killed multiple people.
Humans that gain extra time from a shinigami’s sacrifice will get 100 years on top of what they would’ve lived (since lifespans fluctuate, it would be the last change before the incident). When Gelus died, Misa got 100 years added to the time she would have lived if not for the attempted murder by the stalker (which is 64, meaning that her lifespan at the current time was 83 years). She has a lot of years remaining (164) and would’ve had more if not for trading for shinigami vision twice.
If Misa had only traded once, she might have have lived to be 101 (factoring in the years 19 she’s already lived; the remaining time is 82)! If she hadn’t traded at all, she might have lived to be 183 (at best, her body would have most likely shut down before then)! With the two trades, she might live to be 60 barring murder, suicide, accident, or influence from Death Note usage. 164/4 is 41 + the 19 years she already lived pre-timeskip is 60.
It is discouraged but not completely forbidden for shinigami to love or otherwise favor mortals. What is banned is a shinigami interfering with the mortal plane beyond the scope of their duties. This is why they are stripped of their powers and life if they save a human. They are supposed to be impartial with their duties. Death is not always fair, but neither is life. They are not allowed to toy with the natural order without facing serious consequences.
Ryuk’s shenanigans earned him the ire of the Shinigami King and others (such as the creator). He won’t be getting off scot-free for his part in the Kira case.
While Ryuk states there is no afterlife, I both believe there is and want there to be consequences for peoples’ actions in my fics. Death Note users who do not redeem themselves (show remorse and ask for forgiveness) are actually sent to a special afterlife that is basically a wasteland... and it isn’t completely empty. They will be tormented by visions and memories of every person they’ve killed or otherwise harmed by their actions. Ryuk does not know everything and admits this in canon, so he does not know the specific punishment reserved for humans who use a Death Note. Rem does know and hints at Light’s eventual fate should he not redeem himself...
This is NOT to say that Mu is a place. Mu is a real religious concept and trying to give it a different definition is disrespectful. There is no afterlife in canon!DN.
