consider: roach reincarnation au

so when geralt makes that last wish with the djinn he just wishes that he’ll never lose those he loves

bc he looks at yennefer and is terrified that after that day they’ll go their seperate ways and never see each other again, so the djinn makes sure they KEEP crossing paths

he looks at jaskier and he knows that the fragile human bard is going to grow old and die, so the djinn makes him immortal

and he looks at roach and, well, he knows its fairly unlikely he’ll be without a horse for any extended period of time, but it won’t be the same, it wont be roach.

so the djinn makes sure that it is roach. every time geralt gets a new horse its a grumpy brown one who recognises him and already responds to her name, and thats why every horse he’s ever had is named roach.

(it totally fucks with jaskiers mind when he first sees her reincarnation. geralt mentions roach and jaskier thinks, wow i can’t believe that horse is still alive, until he sees her and its a different - wait no, its the same - what the fuck? he cant blame that on his skincare routine, thats just weird)