19th End Century Memorandum

It does, it was Naver's Novel, but it only available for 6 or maybe 7 chapters, to unlock the rest we have to buy the chapter
Well typical of Naver's completed novel 

She knew that he's not her real brother,  before doing it.
In one of Elliot pov he thought that she's just like her bro enjoying such sinful acts but much later lilain told him that she knew that he's not her real bro. 

I've read somewhere that the novel was way better than The webtoon unfortunately it's only avaible in korean TT.TT.. I hope someone would pick it 

Thanks a lot... 

Yeah there some question and mystery about this manhwa
You can read the English translate on mangahasu or mangago, but they're on slow update 

yay~thanks for the spoilers 

I didn't read the raws but the mangadex comments spoiled it 

Personally I read the manhwa in arabic since it was completely translated. But the raws too are complete & available for free so you could use mtl if you can deal with it XD