So, wealthy single child are greedy and evil by nature? Do you think that being a single child (until he gets the little sister that he asked for) and wealthy, is a valid reason to hate so much not only her little sister, but the friends of her little sister, and try to ruin their lives and even to make them killed?
The character is over the top, as other characters in this game. Adam is a single child, and as most single children, wants a little brother or sister. The he gets his wish fulfilled... and the for some reason, instead of loving his little sister (that even had a serious medical problem, another reason to be protective with her), he starts hating her guts... Why? Because he has to share the inheritance of his father? Just like everybody that have brothers and sisters, and it usually doesn´t make people to hate their relatives and try to ruin their lives and the lives of their friends. Why is he so greedy? Because the fortune of his parents is immense? Another reason for not to be greedy, he´s going to be rich anyway. He´s greedy and evil just because he´s evil and greedy. And that's not a valid reason, just lazy, careless writing.
As happens with other characters in this game, the writer has exceeded himself with Adam, artificially looking for drama.
The romance in this game is great and the girls look amazing, that's why forgive most of the "sins" of the writing. But it doesn´t means they don´t exist.
