Haha, I was thinking maybe Luca died and traveled back to when he didn't join to his fathers family yet.
Spoilerss
He got back again/reincarnated as himself again so he treats the FL well and is cold to his uncle because of what happened in the first life
what happened tho??
Spoilerrrrrssss
There was a scene where the uncle and Luca where attacked so in order to persuade Luca to escape uncle told him that he didn't really treat him as like his son and only did that cause of responsibility (which isn't cause he Totally loves Luca) and on the FL If I remember correctly at the end she is the only one who really care about Luca except the uncle, she apparently sacrifice her life to help Luca (don't remember the exact scene though)
Does luca get to know that her aunt sacrificed herself in the first life?
Yes that's why he trusts her
So i think luca also was 'possessed' since his personality is way different than the original one, or he rlly is smart but pretended he wasn't in the original story which i think has a lower chance of that happening since he wanted to impress his uncle on the beginning.