in order for me....Sasuke- Everyone he knew as his fam Massacred by the one he loved most, his brother, and then he was to believe he only did it to see how strong he was, if that doesnt make u emo, then idk what will x)

Tie between Nagato & Gaara- as we are looking at the worst childhoods...so idk if id take out the killing ur best friend part for nagato, Gaara's father tried to kill him dozens of times & come to find out..the only one that loved him was his uncle...who really hated him...so yea, gaara was alone in the worst way...no one loved him...thats a reason to kill urself

so Gaara then Nagato

P.S i know that gaara was loved & his father was only putting him through that for other purposes