I think the main reason why he hate woman so much is because OGIan's suffering started with a woman. He sees the mother as the root of all his suffering (she is the first to SA him) and he associated it to hestia and all the woman around him. He can't see "man" as enemy even they are also involve to his trauma because in this era, woman are weak and easy to be hated, while men are powerful and he really can't view himself hating those man. Plus his "friends" are from powerful families, and he lacks backing, he can't kill them. OGIan also don't have a solid backing because of what the mother did to him, she assaulted him and the rumors circulates in the noble social circle that he is already a damage heir, and been used by the mother. Making him less powerful in status and he also have a pretty face making it more appetizing to all the man. But because the mother is all the root plus the thought that Hestia is also the same with the mother, plus his lacking solid status, plus the lack of emotional support, plus the "friends", plus all the shit happening to him. This make him not in the right mind and all blaming to the root of all this "a woman" equal to "all woman".

Bro how was og Ian been SAed his entire life omg and also after his “friends” did that why didn’t he start killing men too