I looked for the so-called WN and found out that the author writes it directly as manga, no WN source is even available, are you sure you're not being trolled?
I'm talking about released raw chapter, there are scan float around up to ch 36.It's most likely a misinformation spoiler though, the person in chapter 1 said they read the WN but the author stated he writes it directly as manga. Like how do the guy have spoiler when even the author haven't written it that far?
it basically that only the feMC will be "safe" but the rest has already fallen by the time MC showed up. It isn't true NTR, cause MC only care about the female lead, but he still watching the rest of the casts slowly get fucked by NTRman, all in NTR fashion, of course