[It's not a topic he likes to talk about. Mikasa and him talk about it quite a bit from time to time, but usually they try to forget about the past life of the world they originate from. It's better for their mental health, definitely.]

I told you that there are titan shifters and we have one our side, but several on the "enemy" side. Three of them were involved in a tragedy where two of the walls protecting humanity from titans were destroyed. Those three... infiltrated our military. We became friends with them as they pretended to be the same as us. A lot of us, including me, thought of one of them as a big brother figure, even. We talked about what we wanted to do after we graduate and did all sorts of things together outside training.

[It's an unfortunate tendency of his to spill everything out at once if he's let to do so, just so he doesn't have to explain it again later. Though he explains with a neutral, pretty calm voice, it's clear from they way his hands are in fists that he isn't as quite over this whole thing.]

When we graduated they made another hole into one of the remaining walls. We still didn't find out they were the traitors until a little bit later. And just a few months ago I found out that during the chaos of the fight, they ... [He takes a deeper breathe.] They were part of the reason my best friend died in the battle against the titans that invaded.

[He lets out a rather pained, sarcastic laugh at that.]

Not only did they betray all of us they also killed one of the kindest people who ever existed.


[There are things in the world he can never forgive and this is one of those very things.]