The only salvation for this story, is for the sister to die by the end of the 1st arc, and never ever return again.
If she will remain as the main antagonist, like some generic Team Rocket villain, the story will enter full dumpster fire territory.
Ok, beginning ist the climax already, but if she was presumed dead in the next chapter and she was actually still alive, this has gone to unknown level of Yandere, holy moly.
Anyway! If it's too much for you then you shouldn't read it further.
But, you did read the warning that the manga was messed up right?
Always take caution in reading!! (*❛ω❛)
By all accounts this manga is way better that the worst manga I read, cuz at least here he gets some service without any bloody NTR and ugly bastard tags.
First time I read this novel I feels disturbed and traumatize I can't believe it get a manga with brilliant art but the plot is too much for me I do read dead tube and that is nothing compared to this the goddess character is so questionable I think she is most hated character ever in the series