Something

At first I was frustrated over ML personality. But I m glad after MC family learned that ML was actually just placeholder successor and being abused since young, MC family accept him and told him to think of them as family. They also offer ML to stay at their mansion instead of duke mansion. Ilya also provided ML with successor lesson, MC mother provided ML with swordsmanship lesson.
ML actually never learned swordsmanship, he was just just sent to battle since 14yo and only fight to survive. ML is kind hearted since childhood and very genius and also polite. Showered with love by MC family, ML finally found his own family who love him regardless. Made him no longer beg love from the duchy. He also never forgave his mother when she asked. Because he said, her love no longer important to him, because he already have family who believe in him and love him, regardless all the rumors and even support him. At least, he stopped being such a pushover begging for love.

Background story :
Duke was not initial successor as he was a 2nd son, so he didn't learn successor lesson, and he also lived his life freely also had a lover. But his older brother suddenly died from illness forced him to be a new successor. As a new duke, he had arranged marriage with the duchess (woman he didn't love). He performed his duty to have an heir (ML older brother). So he told his wife he will never love her and as they already have a son, he will never sleep with her again. One time, duke was drunk and slept with the duchess, mistook her as his lover. Duchess became pregnant and ML was born. Duke wasn't abusive to ML but everytime he sees ML he saw his own mistake, so he ignored him. He knew all the abuse, but he didn't care. And he was very much useless duke. The duchy was controlled by elders because duke is stupid.
Blair (ML older brother) has violence tendency. At a time, he realized ML was a genius. So he started blaming all his violence behavior as MLs. He killed ML pet bird, trashing the mansion, stole duches jewelry. And the duchess believed Blair was innocent sweet kind child while ML was irredeemable violent kid. Actually the maids and servants knew about it but they all kept quiet because Blair threatened to kill them if they tell the duchess. Even tho the duke dislike ML because he reminded him of his mistake, duke also terrible father to Blair, as he didn't see Blair was worthy successor. After Duke saw potential in ML, he supported ML as successor, Blair was enraged and killed the duke instantly, the duchess saw it. So she told lie that she will support Blair as successor. Duchess finally questioning all things that happened. She asked Blair that how he was a sweet child who bought flowers from florist and left it on her window. Blair immediately said yes he was. Duchess finally realized it was a lie. Because the flowers are wild flowers that left in front of her bedroom door. She also asked ex servants who worked around the time her children was kid, and they told her Blair was all the culprit but he threatened them. She regretted that she pushed away her sweet child and abused him for years only to keep the violent one around.
After the successor voting, Duchess voted for ML and also reported to elder that Blair was the one who killed the duke. She apologized to ML but ML told her, if she apologized after he return from war the 1st time (where ML bought music box), he will forgive her. But now her apologies and love are meaningless as he already found family and people who love him and see him as he is. Duchess left the capital and back to her own family home. She didn't attend her husband funeral or ML wedding. She works as managing the household, and send her salary to ML to cover the loan she took for Blair.

Yeah I like this tho. MC and her healthy family are such MVP. They helped ML a lot and genuinely like him