Okay I love the feral!76 AU idea. So I thought for a headcannon that Reaper would say to 76/Jack in Spanish: "Matar, mi "pequeña mascota". Matar . . . ¡MATAR!" (It's been awhile since I used Spanish) (It translates roughly to "Kill, my 'little pet'. Kill . . . KILL!") Then when 76/Jack successfully killed someone or something Reaper would say something like this: "Buen chico. Eso es un buen chico." (Like I said my Spanish isn't that great) "Good boy. That's a good boy."
OHHH MY GOSH, I DIDNT EVEN THINK OF THIS BUT I LOVE IT.
Like Reyes figures out quickly that Jack responds differently to the Spanish. He knows he can’t understand it, heck Jack can hardly understand speech, but something about the nature of the language makes 76 focus on him more intently.
It also works a treat for calming down an enraged 76, soft words whispered with rolling r’s and that melodic tone reach to a place 76 doesn’t remember existing. He can’t remember why he feels calmer when he hears that voice speak that language, but he sure as hell doesn’t want it to stop.
For a split second everything was fine, he was home, he was with….
and just like that the moment is gone.
A sharp pain pierces through his head and he shakes it off, trailing after Reaper like an obedient hound once again.