There's more
Iirc, FL was rightfully upset and left her parents' place to go live with the ML at his place. She's angry at the OG!FL too. While living with the ML she learns about her mother who's sick. She met her mother once after begging from one of the OG!MLs (another duke's heir/duke) who is the fiancé of her sister and even then she didn't really reconcile with her mother. ML and FL stay together and their relationship is just very dependent on each other. FL is actually pretty special to iirc, she's one of the few who use spatial magic or something like that which is one of the reasons why the head of the tower wants her.
FL and ML work together along with the other experimented children to defeat the head of the tower. ML and FL never fully reconcile with their family and stick together to the end. I don't remember any marriage or kids unfortunately.
Thanks so much for the novel explanation!! ヾ(☆▽☆)
oh wow thanks for that spoilers, it did shock me to know the OG FL did that to her..thats horrible
right?? I didn't think it'd be the OG FL of all people
What??? Didn't expect OgFl to be a bitch holy
I knew it felt very weird how everyone keeps saying that the fl resembles a lot to the ogfl
I think I read this somewhere before. The premise in the story is that magic is a very valuable resource, but using magic has a very bad side effect to the user, causing them to go under magic overload and to die from it. Which is why only a certain group (nobles) are given the privilege to use magic due to the severe side effects. To resolve the side effect, the nobles group came up with a very cruel plan where they decided to sacrifice a sibling to act as the mana holder for the main sibling/heir as the more related they are to the magic user, the more compatible the mana holder can become. The sacrificed siblings are then sent out to the magic tower to be brainwashed and be modified to be a mana holder, aka they can't learn to use magic, and can only absorb the magician's mana in order to synchronize the compatibility as much as they can which keep the mana pure for the magic user to absorb safely into their body.
Thus, when the OG FL was born, the OG FL's mother was given a mandate to give birth to a sacrificed sibling (FL) to act as OG FL's mana holder. Similarly, ML's family also did the same. ML is originally a noble's son who sole purpose being born is to become his brother's mana holder, but something happens, and the ML ended up becoming OG FL's mana holder instead of his brother.
In the magic tower, the ML and FL were both brainwashed, but somehow the brainwash didn't stick with the ML and so ML is able to recall stuff. (He remembers because this is his second life. Basically a regressor where he decides to protect new FL)
ML brother took his own life after remembering ML and realising what his father and everyone did to him if I remember the previous spoilers correctly. This leads to him becoming the only heir of his family and why his father wanted him back.
While FL's mother actually refused to let FL become used by the tower so she gave her up to a relative but unfortunately she was captured and taken to the tower and had her memories wiped. She believed she was a homunculi not a human. Her sister is the OG!FL who welcomes her into her house, only to stab her in the back and try to turn her into the tower again for her childhood friend, a deceased prince.