Congratulations, you successfully defeated the demon lord and surpassed all the previous heroes who were recorded in history. What! you stole all the demon lord's treasures and plundered all his powers. Are you trying to make a record and become the new one? You monster, how could you betray the kingdom who raised you and sponsored your journey.
You are even more monstrous than the demon lord who shook the entire world with his presence alone, thinking of him gets cursed to death, a single raise of his hand once split the continent in two and you slayed him? The undefeated forbidden hero that destroyed an empire in three days, don't even get me started on demons. Demons are afraid to be around that guy so after the demon lord rose to his throne those guys still haven't left the demon realm to this day and locked the portal connecting to this world.
News flash. The new demon lord eloped with the princess back to the new demon lord's homeland, the world where the hero came from, what. The kingdom is actually corrupted and the princess was treated as a maid and beaten everyday. From that onward, a new history was recorded, the story of the hero becoming the new demon lord and eloped will conclude.
Meanwhile on Earth… The new demon lord reverted back to his previous state before he was transported to another world hiding the traits and his other forms. The princess clinging to her arm and they were living a peaceful life in the city by selling golds from his pocket dimension which is merely a drop of bucket from the mountain piles. With the gold, they recreated the manor owned by the hero after five years prior to construction.
In the past the new demon lord was still a highschool student. Caught by another world to become a hero he spent 10 years of his life there, he has no one to remember him back home. As an orphan he naturally developed some new sense in himself as he saw the fallen kingdoms dyed in blood, wars only happening between eras before his eyes, mountains and villages one night disappeared leaving a huge crater.
Now he is retired living in his manor with his wife who marries him after coming back to this world. He never mustered himself to go back to the orphanage even when only a day passed since he stayed in another world. He has no identity now with his wife, so he forged one with the help of money, having no identity on earth gave him mixed thoughts, the passage of time from another world didn't revert thus he no longer looked like a random highschool student, after coming back here he cries and the princess embraced him to a tight hug.
Through absorbing the demon lord he became more emotional. That's why he eloped with the princess, the demon lord was after all the first hero who had the ambition to take over the world who knelt to a dark god and he personally slayed it alone and remembered how the princess lived in shame her whole life. Some of her siblings tried to get rid of her but stopped, deciding to destroy her life. The arrival of the new demon lord saw her state close to dying, her wounds covered with patches instead of healing her injuries from being battered.
Beaten by the maids and butlers in disgust. She was treated like a commoner in the royal palace, but her bloodline allows her to roam the palace as a maid. Although her blood can heal injuries from minor to fatal, she cannot use it to heal herself.
This kingdom's hatred of the first main wife after she died leaving the princess was transferring all their hatred to her and gossip spreads everywhere in the palace, to the outside her true identity is a commoner, naturally, after arriving in this world she was the only one who healed the hero every time he returned before he became the new demon lord, so the new demon lord obviously developed love and care for her.
He never asked for the goddess if he can return to the previous with a highschool student body instead of now, he entirely regrets it.
He was twenty nine now, and living in the manor with his wife and daughter, the manor was completed several months ago, it was a secret of him having become richer than his country. Through the years of staying in this world, to hide the secret of where he got the gold in his hand, he brought many companies and have them reveal that the true owner of their company is him and his wife, having gold as payment is their way of proving how rich they were.
A month passed, it was the new year. Monsters emerged from gates and many countries fell apart.
Gates appeared in the city where you stayed too, but you took care of them before they took form destroying it with a clence of your palm, of course you have to cover your face so you brought a mask.
Later on you heard on the news that many countries fell and not a single one were in good condition, as expected no one awakened, so as a kind human you have to notoriously spread power over them to help them against this new variable destroying the peace of your life.
You understood that you aren't Superman and the whole world is not only yours to protect, of course you have to travel across the world easily in minutes, but you would be late for dinner prepared by your wife, so as a kind demon lord you took out a ring and placed a library containing all the knowledge of magic taken from another world.
To continue on the life of living in peace with your wife and daughter, you left it behind for the people to discover and learn the knowledge inside.
....
Inspiration taken: Manwha Bon appetit.