Strongest Magus Empire: Harem of the the World Conqueror.

Gray Peace-loving, a normal man who grew up admiring world conquerors like Alexander the Great and Genghis Khan, died one day while playing his favorite video game. Thankfully for Gray, that wasn't the end. He found a second chance in a world that was recovering from a brutal apocalypse, a perfect place for someone with grand ambitions. However, the first thing that he needs to do is take over the village first. While Gray's companions are studying in the village's academy and striving to get good marks so that they can work, our beloved MC is making plans to get rid of the current village head and declare himself as the new king.