Shinigami Physiology

So, I've found a post about what if you had a Death Note and wanted to have my own take on the topic. However, this isn't the one you're familiar with, as it has different rules, some are heavily changed and I even introduce some original lore about death and the Shinigami.

Here's this Death Note's rules...

• The human whose name is written in this note shall die.

• The writer can also kill animals with a name the same way as with humans.

• This note will not take effect unless the writer has the person's face in their mind when writing his/her name. Therefore, people sharing the same name will not be affected.

• Regardless of who the user choses, that person will die of a heart attack (You cannot choose any other method of death).

• Once a name has been written, it cannot be erased.

• The writer can kill himself/herself by writting it's own name.

• The note has 108 blank pages, once every single one has been completely written over, it cannot be used again.

• If the note is destroyed, it will reappear in the Shinigami Realm.

• Any non-Shinigami who uses the note won't go to ''Heaven'' or ''Hell'', suffering the ''Death's Revenge Curse''.

What's the Death's Revenge Curse? Well, when the note's user finally dies, its soul is transported to the Shingami Realm. Once there, the user will experience every death he/she caused with the note and each death will be more painful than the previous. When all deaths have occured, the user will lose all sense of self and fusing with the Shingami Realm, becoming part of it forever and only let a few faint ghostly yells every once in a while. However, a note user can avoid that fate if taking an offer from the Shinigami King, becoming its pet and fulfilling every order given for the next 1000 years. If you succeed on serving him for a millennium, you'll be free to spend the rest of existence as a Shinigami, unless somehow dying. Basically, a Shinigami can only die by saving the life of a human, at the hands of the Shinigami King or ceasing to kill humans until your remaining years are exhausted.

As for what happens to everyone else who dies? Once someone dies, their soul moves to the "Beyond" and there delivers all the information accumulated while alive. That information is sent to the universe's "mainframe", which on Earth is called the Akashic Records, a place where all events, thoughts, words, emotions and intentions that have occurred anywhere are stored. Following the theme of ''the universe being like a computer', the Shinigami can be considered as the ''administrators'' who rarely intervene with the inner workings of the Physical Realm (Also known as ''Human World'').

Despite that, there is no Heaven or Hell (Only the Shinigami Realm), since everyone goes to the same place and receives the same process, since the universe (And other possible universes) has no sense of right or wrong, it treats everyone in the same way and brings cosmic balance. Once all the information has been delivered, the soul is restored and returns to the universe, being imbued in a new being that has at least a tiny connection with its past incarnation (Like loving the sea and reincarnating within a family of sailors).

By the time the universe suffers from its heat death, organic life will already be extinct for eons and since there are no more physical bodies, souls will not reincarnate. That means they will either merge with the records permanently or be downloaded into a parallel universe where there is organic life. Also, babies and most animals will reincarnate instantly, as they don't have enough information to process.