The Sage Was Reincarnated for Five Hundred Years

One of the six brave men five hundred years ago, After death, he was reincarnated as his friend's descendant, A side branch of the 'Efield' family. I don't understand why I didn't die, and I don't understand why the secret method I created was not passed down. And, The demon clan, which should have been suppressed, has been on the rise again in recent years. "This body is so weak... But the talent is okay..." With a mind full of doubts and a new body, Harry Kahn entered a new era.