The Demon Lord Returns!

Summary: Many centuries ago, you were a great and powerful Demon Lord, many women wanted to be yours, and you lived a luxurious life. However, one day all the other races united and attacked the demons, fearing them and envying them, although in fact it was the rulers of these races who feared and envied you. As a result, after numerous battles, the Hero and his gang, whom he calls comrades, were able to defeat you in a vile way and seal you in a remote cave. Tens and even hundreds of years have passed since then, and suddenly a girl archaeologist appears in the cave and accidentally breaks the seal holding you back.