Dorian pushed the humiliation to the back of his mind. He decided that he would first improve himself and one day he would enact his revenge on these noble brats.
At this point, he was not strong enough to compete with those nobles, so he decided to improve his rank first. He would have a lot of time for his revenge later. He only saw the noble brat as a small hurdle and a one-time thing. With the system, there won't be too many hurdles for him. This was his thought.
It wasn't until he went to the Magic Association that he learned that the hurdles had only started to appear.
His Tier-1 promotion mission wasn't easy. He had to kill a Tier-2 monster in order to be promoted to Tier-1. This was like an insane mission that anyone could get at that point. He was peak Tier-0 and it would be considered difficult if the monster that he had to kill was at mid Tier-1 or something.