When it sped up through him having a good relationship and a happy life, I kinda got the feeling that she was absolutely doomed. And ayup. Good setup, though I wonder how much more tragedy is coming our way too. Kinda reminds me a bit of Buta no Fukushuu to be honest. Though in this case, it's the karmic result of his failure in his past life coming back to haunt him in his isekai, whereas in Buta no Fukushuu, it's really just absolute misery lobbed unto a guy who didn't deserve it despite him trying to do everything right, to the point of absolute comedic level of absurd cruelties and villainy.