There's Something Wrong With This Account - Chapter 450 - : 450, [Realm of Mystery]

In this fantasy world, music and aether rules all. However, there is constant threat of demons and natural catastrophes. The most powerful men are musicians who use music, alchemy, and spells to safeguard their homes. A young man who just wants to find his father and know why his family was exiled, starts his journey of becoming musician – a journey that leads him to the crown of justice and glory.We are born of aether, grow under aether and die as aether. Awe of Aether! – Holy Code.

Su Xiao is a cold-blooded teenager who’s seeking vengeance for the death of his family, yet things ended up badly for him.

As he was taking his last breaths, he heard a voice calling him from dimensions, it was a strange system reaching him, asking him if he wanted to be saved, to be Reincarnated.

He just needed to accept a contract, Su Xiao didn’t have any choice but to do so, but he didn’t know what he signed up for!!

Traveling through worlds, doing extremely dangerous missions, collecting special items, leveling up, and even killing Protagonists…

But Su Xiao wasn’t any ordinary Contractor, Su Xiao was a Hunter!

The MC crosses over to: One Piece, Tokyo Ghoul, Naruto, Fullmetal Alchemist, Attack on Titans…

- Description from Novelupdates

To save the hopeless Dark Fantasy World, I held back my tears and destroyed the world, then killed the Demon King and returned.

Now, I’m trying to save the world using the ‘System’ I gained as the ‘Regressor’s Privilege’… but the Main Heroines have also awakened their memories of the previous timeline.

God damnit.

“O, Hero!” With that cliched line, Kazuya Souma found himself summoned to another world and his adventure–-did not begin. After he presents his plan to strengthen the country economically and militarily, the king cedes the throne to him and Souma finds himself saddled with ruling the nation! What’s more, he’s betrothed to the king’s daughter now…?! In order to get the country back on its feet, Souma calls the wise, the talented, and the gifted to his side. Five people gather before the newly crowned Souma. Just what are the many talents and abilities they possess…?! What path will his outlook as a realist take Souma and the people of his country down? A revolutionary transferred-to-another-world administrative fantasy series starts here!