MTL - Marvel: Start with God of Destruction - Chapter 290

«Grey, elemental affinity, zero» The Elder announced the result loudly.

Depth-Dwellers are long extinct.All except for a single one..Waking up after being dragged by the pressuring tides, Cetas finds himself in the middle of an unfamiliar ship, greeted by a distinct group of pirates.Without any knowledge about humanity at all, he traverses the seas with the unknown band of pirates and learns about their culture and speech. In a world where 'Zeal' serves an essence for humanity's power, Cetas must learn to ascend the ranks to protect those that he cherishes.For when the mysteries beyond the fog arises, the Dreadspawns begin to wreak havoc, and the Leviathans rise up into the world..'Would Cetas become a 'human' worthy of saving those that he loves?'

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

Cairn is a prince who is already tired of ruling. Faced with an imminent coronation and an overbearing father, he wants nothing more than to drown his responsibilities in cheap liquor and poor decisions. With the help of his sister, he hatches a plan to escape the clutches of the throne once and for all. It all goes terribly wrong, and Cairn finds his priorities shifting in the face of unimaginable tragedy. The change of heart comes too late, however, and Cairn dies. He reawakens to find himself transported ten years in the past. He immediately begins to plan for the future, only to discover his killer has somehow followed him. To succeed, Cairn must unite the kingdom and discover the motivation of his killer, using as many tries as it takes. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++I exhausted pretty much every time loop story ever written and decided to write my own. You'll see a few similarities here between this story and some existing stories, at least initially. There's a lot of inspiration drawn from both MoL and Re:Zero, though in terms of pathos and darkness, this story leans more towards the latter. Be warned, it is something of a slow burn. The main character will grow and become powerful, but a theme of this story is that power comes slowly and often at great cost.