So, I wanted to bring up the concept of immortality in hetalia and how I personally think it works and how I like headcanoning how it impacts a characters relationship with the idea of 'dying' in the sense that some of them take advantage of this immortality, not really really considering the consequences of dangerous actions while others are still almost just as wary and cautious as a mortal human.
CW: mentions of death, idiots doing stupid things to see what happens.
I will be reblogging this on my general hetalia headcanons blog because it applies to my entire AU and not just the Nordics, but I will mostly be using the Nordics as examples here because this is a Nordic centred blog.
So, let's first get into how I think the Nations' immortality works.
Their immortality isn't an inability to die. They die all the time. They're a bit more resilient than a regular human, but if you were to chuck them into an active volcano (provided they're not resistant to fire as a result of their geographical features) they would likely die.
The immortality isn't on a spectrum. What kills Iceland is just as likely to kill America. What differs is recovery time.
When a nation dies, it's almost like a coma. They typically cannot feel, hear, or see in this state. The recovery time is based on two major factors and a couple minor ones.
The main factors are the severity of the cause of death and a nation's individual will to come back to life at the expense of proper recovery.
Let's bring back America and Iceland for a second. Let's throw them both off a cliff. Same distance, same injuries and same stable conditions to recover in.
Let's say Iceland takes about 1-2 years to recover. He wakes up perfectly healed, no pain whatsoever, not even a scratch.
America wakes up after only 5 months. He's still in pretty rough shape but he'll survive. Maybe a couple broken limbs, ton of scraps and cuts, and excruciating pain, but he's alive and he'll recover eventually.
The cause of death is also a major factor for obvious reasons. If I completely obliterated Denmark into smithereens, he's bound to take more time to recover than if I stabbed Norway. This is actually a great example because a nation actually being hurt beyond recovery leads to a whole new reformation of their human body which takes a really long time and a nation can't choose to wake up early from. A stab wound would naturally mend in a few months.
Minor factors are like the conditions of their recovery, external medical assistance, etcetera. If you personally go in and fix the damage caused by a stab wound, the nation will likely recover and wake up faster.
There are factors that make certain causes of death easier to recover from for certain nations than others.
If a nation experiences a certain cause of death a lot, the recovery time will slowly decrease.
For example, hypothermia.
I headcanon that when Iceland was born, there was a period of time he spent literally just freezing to death over and over again. He was born in the snow with no idea what to do or where to go.
Nowadays, if he were to die due to hypothermia, he'd recover in maybe a month while it'd take America almost a year.
Now let's get into how immortality impacts a character's relationship with their numerous deaths.
Someone like Denmark or Finland would absolutely take advantage of this power and use it to experiment with different ways they could exploit this ability. It makes them stupidly brave, and they never exercise even a bit of caution before doing something stupid because they'll just 'come back again' it doesn't mean they'd just toss themselves off a cliff for funsies, but it does mean that they're more willing to take risks because they have nothing to lose.
People like Norway and Sweden don't use this ability to do dumb shit. They actually operate mostly like a regular human. It's partially to do with the fact that they have people they're responsible for. This immortality does make them hesitate less when they have to act dangerously in order to defend either themselves or their aforementioned 'children'.
Iceland treats death exactly how most people do. He's cautious, and he still reacts to threats with the same fear that a human would react with. He's still very aware that he technically cannot die, but it doesn't mean he's about to play around with casually dying every once in a while.
Each nation has a different philosophy regarding their immortality.