I really appreciate how this arc ended. I seriously thought that the creator was blowing their payload off way too early/that MC would lose and it'd become a tedious cycle of his sister winning and making him suffer further. This is a way more interesting premise.
Actually, I get that she's almost certainly going to reincarnate and go after him again in his current life with even stronger tactics that he'll have to big-brain his way out of, but there's also the possibility that he'll live out his life normally, reincarnate in yet another world and that's where she'll meet up with him next in the hopes that he'll have less OP powers this time.