What's the point with that quite lackluster story in Endwalker?

[Rulakir]

I'm trying to remember exactly how the threat of Black Rose ended, can't remember if it was Zenos or Gaius's group who destroyed the last batch. There's a lot to cover in SHB's story to pinpoint the exact point.

Fortunately, I just finished going through ShB again, it's "Vows of Virtue, Deeds of Cruelty" at the end of 5.1. Estinien tells you in the Rising Stones: "Until order is restored--assuming it even possible--we needn't fear an imperial reprisal. And for reasons of his own, Zenos took it upon himself to rid the world of Black Rose."