Yay!
Half-chapter backstory trying to legitimatize the actions of a piece of shit!
Who the fuck cares? I'm sure that most shitty people have "tragic" backstories... and I still don't fucking care.
When you steal, betray, and try to kill people? Please fucking die; I don't give a shit about your meen poopy school-life or family trauma, I care about what you did.
Shittons of people have horrible trauma, and they cope with it by NEVER PASSING THE TRAUMA ON
If you can't do that, then you can stop passing that on (in the isekai world) by dying, thank you.