Harol knew that his father is the Tower Master. It's just that he thought he left them and never loved his mom since she died while giving birth and couldn't tell their love story. and the mom is also from the magic resistant faction (which is the opposing group of the mages) moreover, Tower Master never knew Harol's existence, he never knew that the woman he loved gave birth to his son and so, if he never visited them nor acknowledged Harol, (and obv continued to be the evil Tower Master that ended up dead) it definitely resulted to a huge misunderstanding for Harol and yep, his rage.
Yeaaah, the 'truth' he didn't know was pertaining to the love between his parents. Since the both of them were from opposing factions Harol prob. thought the Tower Master deceived his mother. It was also mentioned she died giving birth "alone" and didn't know about him, that's what fueled Harol's hatred to his father, and prob. to mages cause he can't use magic despite being a half. I was also rereading the novel at the moment and loved this part, that's why I have a good grasp on it hehe
‘However, there was something Harol did not know.’
It was something only the author and the readers would know. That one line was enough to make Harol’s anger worthless.
< Harol Kodiang. He was a product of his parents’ love, but unfortunately, he would never know the truth. >
The novel did not go into detail about it. All it said was that the liege of the Magic Tower met her when he was out training as a young mage and fell in love.
Harol Kodiang's background is one of my "What ifs" in this novel, I just can't imagine how unsaid truths could have changed a lot - the war, the deaths, especially how magic was used in the Whipper Kingdom and its influence in the main story (White Star and Empire). Of course, it's just me making it a big deal but yeaaah he's a love child and it just makes me feel sad somehow