IM BACK FROM IMMORTALITY

Ken, a high school teenager likes roaming around the city and get into trouble by fighting random citizens. One day he accidentally went inside the underground world, where all fighting and betting starts. He registered to battle one of the warriors there but, he didn't know all people that are inside of that world are all cultivators. He lost and died, but the guard of that world decided to give another chance and sent him to a world where he will rise to the top, and dominate all light and evil being known as the overlord. He reached the pinnacle of Martial Arts and Magic and defeated all Monks and Demons inside the Battle Tower of the 99th Floor! But, he was sent back to earth unknowingly stayed in the same position as when he was back then before entering the New World. "1092 Years of training and cultivating has been all wasted! Pathetic humans must pay for summoning this Overlord! I've reached Immortality and stand at the pinnacle of the world how can a mere dream sent me back here!". and there he started finding ways to reach Immortality on Earth which has the most Spiritual Essence for greater training!