Hear me out (NO, it's not the kind you are thinking)
We know Death has a job, right? To collect souls and most likely release them to the afterlife.
And for this job, he has to be there when somebody is about to die, as demostrated with him being there moments before Puss' eight death.
Supposing he is THE Death and he has been doing this since the beginning of time (or at least when there were enough stories of the Grim Reaper to adquire a physical form) that means he has seen a lot, A LOT of awful things.
Murders, suicides, massacres, death of infants, people who didn't deserve to die alone, animal cruelty, some other heavy stuff I won't mention here, etc etc etc.
And we thought "man, how is he able to cope with all of that? That job has to be utter torture for someone."
Probably many of you could think that he is able to do that because he is Death, and he was "born" with that purpose and only him can reap souls perfectly.
But while he is a force of nature, he also WAS a force of nature. Let me explain it well: He adquired a personality enough to be angry, excited, frustrated, amazed, happy, among other emotions.
While he has supernatural power and is most likely the most powerful being in the Shrek Franchise (or in Dreamworks as many say) he is also a PERSON.
Someone with a code of honor, morals, opinions, beliefs, etc.
Returning to the question "How can he bear all of that?" taking into account he is no longer an inevitable force, but a character of his own.
The answer is something you may relate to, and that is: Creativity and escapism.
To be the embodiment of Death, the guy is a very creative fella.
First of all, his design. I heard many people saying here and in Twitter that his design is something they would come up in their edgy, teen years of drawing their first fursona.
Guess what? They are right, the wolf form is someone's fursona. It's DEATH'S fursona. He clearly came up with this badass, piercing canine form to blend with the Fairy Tale Land assuming the form of the "Big Bad Wolf". He most likely had other forms he designed over the centuries and was able to present as them like if he were on a role play game in the living world.
His sickles? The weapon of choice with the little crossed cats on it to have a bigger effect of terror for Puss? Those who can become knuckles and join to create a scythe? Those are his creation, probably after thinking it for a while and writing all of those functions on a paper.
The way he presents himself? In the bar? The coins in his eyes as a "watching you" sign while being a cool reference to the Ferryman of souls? He transforming Perrito's forest into the background of a skull? The chilling reveal at the Cave of Lost Souls? The fire ring? It was all him.
As for the escapism part...
When the world becomes too heavy to deal with as real life issues tend to make us feel bad, depressed, angry... we tend to escape it somewhere. And in our time the common place would be the internet as in webpages or comics, stories, etc.
But what has to do with Death Wolf you may ask?
Well, while he would NEVER be able to escape his job entirely, he can have moments where he can enjoy a good hunt of people who don't appreciate life, like the whole plot of the Puss in Boots sequel could demostrate.
He managed to have a little time outside his eternal routine to chase an arrogant cat who took life for granted. He enjoyed it, it was thrilling, it was exciting.
It was a way to escape a monotonous, grim "life", if just for a short moment.
So, when the chase ended as his prey no longer feared him and now was ready to fight for his last life, the wolf retreats, happy for Puss' character development but resigned because he once again had to return to "The Eternal Duty"
And that's not even counting all the times Jack "I'm dead inside" Horner had to interrupt Lobo's hunt and remind him of his job even in his "spare time"
Death knew the chase had to end eventually, but he didn't want it to end.
He didn't want to return to his own world
And if we look at Death like that, then he is probably one of the most relatable characters Dreamworks has ever make.
Princesses don't have to fit the perfect standards of beauty
Handsome guys can be possesive jerks
Love at first sight doesn't work like one would think
Happily ever afters had to be built and not just obtain them with magic
And Death is the most creative and "full of life" being in the world
Because he would absolutely go crazy with his life/work if he wasn't.
Because in a world of Kings, Poets and Soldiers, he's the Supreme King
And he's also a perky goth but none of you are ready for that conversation.
