I forgot the name cuz A03 is down. It has "Jellyfish" in the title or sum. But its Arcane and its JayVik and its what happens to them after the finale. They live in the wild and they fuck and the writing is beautiful like holy Shakespeare.
My favorite is a SatoSugu one called Blue Corner, it takes place in an AU where Gojo is a top boxer and Geto is an reformed illegal boxer. It is so amazing and I love it so much, definitally reccomend!