One Billion Civilizations Live in My Body

The aliens are too weak, they only know fleet combat but not strategy; they wear mechas and don't know martial arts. Lin Xuan traveled to an alien planet and had no interest in usurping the throne. He only wanted to gain military power. I have the fleet, I have the galaxy! "Master! The number of galactic civilizations in your body is increasing by 1,000 every day. Do you want to recruit two of them to come out and fight?" "Your Highness Sixth! In order to find that small corner of the earth, you have united so many galaxies. When will it be over?" [Time travel + evil + science fiction + overlord + what should I do if I hate the heroine]