I will not do anything past 2020 for the history sections unless they were born after 2020, as many events are too recent. Website still incomplete.
Personifications can be killed. However, that does not mean they will stay dead. If a personification is killed, or if they die of disease or something else of the like, they will come back. If they are killed by something that would leave a scar, a scar will remain, and if they are in country form and it is dark out, the scar will glow. When they are dead they are taken to the afterlife (explained in more detail in Afterlife).
Additionally, to protect their mental state from trauma, personifications are unable to remember the final fifteen minutes before their death. If a personification is killed in war, for example, they will wake up from death but not remember how it happened. This can sometimes make it hard for a personification to recognize that they have died, especially if it is a death from something like disease, which leaves no glowing scars.
However, if a personification gets stuck in a situation where they are unable to come back because they die as soon as they revive (i.e., a death loop), they will remain trapped in that loop for a maximum of two years before they stay dead permanently and are given a replacement personification.
Sometimes, a personification can also get caught in circumstances where it is impossible for them to revive because the thing that killed thing is still killing them. Now, if it were a bullet caught inside them, their body would push the bullet out as they revived, and if they lose some major organ or their head, there is a chance of them being able to regrow it, but that is very circumstantial and would rely on the health of the land and people itself to fix that. But, things like freezing to death and not getting anywhere warm will keep the personification in a post-mortem state, and like with the death loops, they will eventually die permanently, with two years being the maximum they will remain in that status.
Very few things can permanently kill a personification. The most obvious is, of course, the dissolution of whatever government they have and the creation of a new one. There is also the aforementioned death after being caught in a temporary death-death loop and the "circumstances in which they cannot revive," which will eventually result in permanent death if the personification is not able to free themselves from it in time. Outside of this, there is one more way in which a personification can be killed permanently: at the hands of another personification.
If a personification kills another, they will die. No resurrections, no coming back. Being killed by another personification will result in them dying, with no do-overs, no matter how important their country is. They will not be able to come back at all. Which does pose a problem if, let's say, the USA was killed while his country still existed. Now you have the issue of a country without a personification, which is an issue. That brings me to my next points: replacements (also called reincarnations).
When a personification dies, but the land/people/organization they represent is still around, the deceased personification is replaced by an aptly named "replacement," which can also be referred to as reincarnation. The replacement personification will restart the aging clock and can be of different gender and sexuality and the like. They are not the same person as their predecessor, despite the idea that they might be. They are effectively a new personification for the area, although they can have the memories of the deceased personification. The memories tend to be faint or more dreamlike, but the longer a replacement lives, the more of the former nation they can remember. The one thing they will never be able to remember, however, is how the former personification died.
For replacements themselves, there are three ways in which they view themselves and their relationship to the former personification. The first is as the same person as their predecessor, and attribute their lack of memories to amnesia, like the State of Delaware. The second is that they are the child of their predecessor, and they are their predecessor are two different people. Lastly, they view themselves and their predecessor as two different people who are not related and simply represent the same people (although some may use familial titles, they are not a relationship indicator, but rather a title, like in the case of the Ingrian Finns).