Read Reincarnation Of The Strongest Spirit Master by Ranmaro

William found himself twenty years in the past after being killed by the mighty nine-tailed fox monster.

He was an eleven-year-old worthless kid with no spirit and weak spirit power at the time. He worked as a porter in a prestigious academy, serving other students for a living.
But the person who went back in time realized it wasn’t the end of the world. Many people were unaware of William’s abilities. So he’ll train and grow stronger, eventually becoming the world’s strongest spirit master.
He began his long journey to becoming a true powerhouse from such a low point. Despite using all of his previous life knowledge, he would still face numerous challenges in the academy and throughout the world.
Nonetheless, William will triumph over them all. His main goal will be to grow beyond the limits he reached in his previous life, rather than simply being something in this world.
He wished to better prepare for the hideous and lethal enemy that had killed him, the nine-tailed fox monster.