How to use XXXIV
- The owner of the Death Note cannot be killed by a god of death who is living in the world of the gods of death.
- Also, a god of death who comes to the human world, in the objective to kill the owner of the Death Note, will not be able to do so.
- Only a god of death that has passed on their Death Note to a human is able to kill the owner of the Death Note.
As the rules are grouped together, it seems they are related. In context, they imply that gods of death cannot kill Death Note owners with the exception of the original owner. Keep in mind that the rules seem to be a collection of observations; not the "programming language" of the Death Note. This means some wording may not be perfect. In practice, Light was able to kill Death Note owners whose original owners were not shown to also write down their names.
Also, note that everyone already has an expiration date so they are never immortal from non-Death Note related deaths.
That being said, that interpretation sounds as if an owner who found Misa's old notebook after the Shinigami was dead would effectively be immortal or at least immune to all Death Note users. This seems unlikely.