SO his mom was endlessly de facto raped and impregnated until her body couldn't take the strain anymore and she died. (And I don't know if this makes it better or worse but if the gestation period is shorter that means that she had to be raped more often and give birth to hundreds of those things but if it's longer than it means she had to carry them in her womb)
And so know he has all these Hollow Knight-esque failed siblings that are botched experiments out for blood.
Holy hell is that grimdark.
I know. The more you think through the logistics, the worst it gets. @Sonaldo
NTR implies she ever became fully willing, which I doubt...And god only knows if his uncle did anything to her himself...@Is1026
@Tamerlane NTR has nothing to do with whether they are willing or not. Its just that its either rape or they are willing. Out of those options most find the first to be the more "normal" one.
The end result has nothing to do with whether its NTR worthy or not.
The root of the word literally means "taken away by sleeping with." It means at some point they "switch sides" at some point to the person doing the NTRing. Otherwise, it's just cheating.