Although he was never fond of his youngest son, who often stubbornly contradicted him, he was still satisfied with his past performance of loyalty and bravery.
A family member with a stubborn head is quite suitable for consolidating his own authority and the future reign of his elder brother.
But now, such treasonous words and deeds are something that Baron Shatai cannot tolerate; his authority being publicly challenged is unacceptable, even if it's by his own son!
Yevan did not feel ashamed by his father's interrogation; comparing his former Lord, Lord Sevin's behavior, he grew even more disdainful of his biological father upon the Lord's Throne.
"...Rebellious? No, it is I who disown you... Father, you are not worthy to be the lord of my loyalty."
