Marvel: The Ultimate Superman - Chapter 236 - 235. The Deal

With the revival of spiritual energy and the breakdown of the order of species, it is a difficult test whether human beings can still stand at the top of the biological chain.

(There is already an old book, The Strongest Descends in the City, you can read it.)

- Description from novelbuddy

Humanity’s first 8th Class Mage.

Betrayed, he traveled back 30 years into the past.

The story follows Ian Page, archmage and the first man to break through the 6th class, then through the 7th and become the most powerful mage, an 8th class mage.

After a lifetime of war and killing, the continent was finally unified thanks to his efforts. Now, old, his wish is to live the rest of his life in peace and try to find salvation for all the blood he spilled. However, his old friend, maddened by paranoia, couldn’t tolerate someone so powerful, so he betrayed Ian and killed him.

In his last breath, he cast a time magic that allowed him to travel back to when he was a young boy. With all the knowledge he previously had, he decided to do things better so he could end with less regrets.

Transform into Divine Dragon and dominate the world!
He is the only Divine Dragon in the sea who founded an underwater Dragon Palace.
With Crawfish Soldiers and Crab Generals as his followers, wild sharks and gigantic octopuses as his subordinates, he is the dragon that rules the city.

- Description from Novelupdates

Lucian, a guy who can exist in both times, day and night, was chased by both. An enemy of the world. A survivor who thought he was a hero, a world saviour, but it wasn't as he thought; he wasn't a hero, he didn’t even know the truth, the truth he knew was flawed, causing more harm than help to the world.When he got to know the truth, it was already too late. The world had fallen, but it wasn’t the end. It was the beginning of destruction.