
why was her blood green?

Her blood is red there just isn't a lot of it most likely for censorship the green around her I think is the melted ice not sure why the water is green maybe it was poisoned who knows could be spinal fluid but I don't think that's green or could just be like Danganronpa and turned green for censorship like they turned blood hot pink

So they Mother and son?

But what if Lilith and Lily are actually the same person and the baby in the flower thing is actually a rituel that permits Lilith to never die by a system of reincarnation but since Min took the the flower too soon, her memory didn't pass directly to Lily as it should have been and like Hill who has been sleeping to the point an other personality grew which is Doh Hyun, Lilith did the same with Lily...
Or what if the baby in the flower thing was a last resort for Lilith because she got too damaged from the fight against the blue lady(I realized I like this theory better)
But yeah I agree she definitely wouldn't be his mother, it would be too weird and that means she wouldn't be her waifu(well technically she could but that would be awkward)
20 years later and this manga wouldn't update i bet... (〜 ̄△ ̄)〜
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It updated and not 20 years laters hahahaha