My System in League of Legends Is Very Arrogant

Lin Han traveled through time. This is a world dominated by the League of Legends, but he has technology that the League of Legends does not have in this world. He also got a system, but this system is a bit arrogant, but the rewards are still very generous. This is my first book. I don't know how to write it, so I hope I won't criticize it. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.