I would say Nico, because he fucking died at the age of fourteen after being involved with a fucking CRAZY ASS CULT AND BEING IN LOVE WITH THE LEADER

But then there's Noiz who was literally shunned and abandoned by his family for something he couldn't help...

And Senji had to watch his best friend die while he was surrounded by his other friend's corpses...

And Germany kind of has to live forever, so I'm sure he sees a lot of shit

all your characters are depressing as shit

I don't...............know................

I KNOW

Every single one breaks my heart in some way

The only reason I'd say Nico is because he's a elementary/middle schooler who got involved in something so much bigger than he thought and the person who he trusted the most betrayed him and his trust.

But at least in the end he was the one who brought down said person and he died knowing the truth about them