The School Life of the Earth Leader is a Manga/Manhwa/Manhua in english language, Isekai series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The strongest being on Earth, he always yearns for a fight that will excite him. Driven mad by his obsession with battles, he eventually possesses the body of a high school student to once again relish the thrill of combat. Will he be able to overcome the stuggles in his new body and continue to indulge in the joy of battle?