Oh my god this is *adorable!* I suddenly realize why everyone suggests this
>>50170671tl;dr a XY fix-it fic where an incident early on In Ash's journey sets him and Serena on different paths. Serena ends up taking the Gym Challenge and growing into a legitimate rival for Ash. Ash does a little bit of soul searching and decides to bring back a reserve while going to catch up with an old friend.
It's Latias, he's catching up with and catching Latias. Currently just outlining and need to make sure I have the plot sorted out before I start moving things around more heavily.
>>50170680Nah this is a XY fic so SM's continuity isn't important to it.