I know its not gonna happen, considering the author's previous works...
But man I really want to see them leaning into the PTSD angle:
"You just don't turn it off! It wasn't my war! The King asked me, I didn't ask him! And I did what I had to do to win, but then I just get kicked back here! And I come back to this world, and I hear them calling me 'illiterate' and 'chuuni' and all kinds of vile crap! Who are they, huh?! Who are they, unless they been me and been there, and know what the hell they're yellin' about?!
In the field, we had a code of honor: You watch my back, I watch yours. Back here, there's nothin'! Back there, I could ride a wyvern. I could command spriggans. I was in charge of million-Drake artifacts! Back here, I cant even get a f**king scooter license!
Oh, my God. Where is everybody? Oh, God. I had best friend, Acilia. I had all these adventures friends, onii chan. Back there, I had all these comrades, who were my friends. 'Cause back here, there's nothing. Acilia always wore this black headband, and I took one of those magic markers, that I said she found. She said mailed it to the Capital, 'cause we were always talking about the Capital, and her enchanted broom, she was talking about this broom; she said we were gonna fly along the Niben River 'til the enchant ment wear off.
but... But there was this f**king lich, this f**king lich we missed... and it blew her body all over the place. And she's laying there, and she's screaming, pieces of her all over me, and I'm tryin' to pull her off - My friend that's all over me! I got blood and everything, and I'm tryin' to hold her together, put her back together, her insides keep comin' out, and she's sayin' "Hey, I wanna go home." She keeps calling my name! "I wanna ride my broom again" I said "With what?! I can't find your f**kin' legs! I can't find your legs!" I can't get it out of my head. Every night, I dreamt about this, And sometimes, I wake up, and I don't know where I am. I don't talk to anybody. Sometimes a day...a week......I can't put it out of my mind."