I'm getting PTSD flashbacks of Kazusa True. WA2 spoilers, Atri do NOT hover:
>Setsuna slowly going schizo over the route, like a lot more schizo than normal
>Setsuna gets hit by a bus
>ending kinda implies that Setsuna is dead because the game doesn't address Setsuna's fate till the epilogue
>Kazusa & Haruki receive a package in Austria of Setsuna playing an acoustic guitar