Responses
as far as i can remember, the concubine wanted revenge because she got pregnant by some random guy since the king is infertile; she wants her child to be the next(?) crown prince. unfortunately, her child died so yeah she wants to avenge her baby
as for the sisters, the mother only pays attention to their brother. their mother only sees them as (im not sure) "assets" by wedding them to noble men. the sisters dont feel safe around their own family, so they decided to turn their backs
(correct me if im wrong to those who have read the novel)
i finished the novel weeks ago, but i noticed there are plenty of details not discussed in this manhwa.
like the cause of the concubine's revenge and what made the sisters finally betray their mother and brother