It's alright but it's just a feel good revenge story. There are certain aspects that could be improved. For example, the main character's revenge. It's all just reckless fighting while hoping that luck will allow him to beat the heroes. He doesn't really create plans or think through his actions, and he never learns even when he takes loss after loss. After a while, you start to feel less bad for him when he inevitably loses someone important to him.
A good example is the princess arc. For some reason, he completely trusted a former classmate to betray one of his other classmates. He KNEW that there was a very, very high possibility of betrayal yet planned nothing in advance should he get betrayed, so, when it inevitably happened, he was stuck there like an idiot with surprise and anger on his face. He only ended up winning because he relied on luck, which has happened twice now- winning because of pure luck and, dare I say it, plot armor. The whole situation could have been avoided had he made a backup plan for the very real possibility that he would get betrayed.