1.Not Once But Nine ?

In the Unknown Universe, Two Ancient Beings were on an endless struggle for supremacy as they fought with each other since the start of time. One was the being that governs the law of light while the other was a being that governs the law of darkness. Due to the conflicting powers, they kept on fighting to move across the universe in order to replenish their powers to keep on fighting. The cost of replenishing their powers came at the cost of countless stars, planets, and other forms of energy. Since the battle between the ancient beings brought endless destruction and devastation of countless planets and life forms, the other Celestial Beings used his powers to cast the two beings into the revolution of samsara to undergo the duel of reincarnation in the mortal realm.

The ancient beings were supposed to fight with each other in Nine Different worlds as Nine Different entities with the memory of only their past life as each time as they go through with reincarnation. They were subjected to memory loss as they are born into the world. They would then gain the knowledge and memories of their past life when they reach their 10th birth cycle. The beings were each allowed to retain one of their abilities to win this fight and determine the winner of this Reincarnation Duel.

In their, First Descend the being of light was born as a little female wolf pup named Kaila while the being of darkness was born as a little Lion Cub name Azaroth. It was a world dominated by godly beasts and evolved ferocious beasts who could turn into Demi human form when they reach adulthood. The world was divided into territories among different beasts. On their 10th birth cycle, both beings fell into a coma for a day as they received their gift. Kaila receives her [Celestial Intelligence Talent] and Azaroth Received his [Devourer] Talent. With time they both grew enlightened and grew up into leaders of their tribe. Kaila became the most beautiful woman as she revered as the godmother of all beasts, Whereas Azaroth with his power became the one who would engulf everything to gain power.

But Azaroth didn't like Kaila being above him in terms of status, so he waged wars and threatened to destroy all who opposed him.

The first duel ended as a loss to Kaila since she was betrayed by her tribe and offered as a sacrifice to Azaroth who demanded her to be handed over or else he would devour their entire wolf tribe. Although Kaila was equal in terms of power she relented and killed herself for the sake of her family.

As soon as the first duel got over the world went on with Azaroth conquering everything and ultimately becoming the sole ruler of the world.

As the Second duel started with both the beings of light and darkness being born into the early warmongering period of a medieval world. They both grew up into different personalities and traits. The being of light was named Arthur born in a military family of a lowly country, after his enlightenment, he started mastering the different martial forms and all kinds of weapons with his Celestial Intelligence.

He became the Martial God of his period and built up his army for his King as he conquered every land he was pointed at. While the being of the dark was named Diablo who used his Devourer to gain power by killing his enemies as he soon grew into the Commander of his kingdoms army and was nicknamed the God of War. The Conquering continued till only both the empires were left in the world and they eventually met at a face-off. The Battle started with both the army's battled it out for days without rest until both the kingdoms signed a contract to hold a duel with their gods. As Arthur and Diablo eventually faced off each other they both had a vague feeling that they had met each other before.

Their battle devastated the area and they battled for 10 days and 10 nights straight until they felt something was wrong with each other. It seemed that both of them were poisoned by their own countries. They were both betrayed by their own kings and died due to poison as they both died with regret.

The third duel started in a fairly modern world where humans have prioritized in technology advancement. The being of light was named Alexander and was born into a medium rich conglomerate family. And the being of darkness was born as Klein, the son of one of the biggest underworld masters. They grew up and after attaining enlightenment. Alexander Became one of the most successful businessmen in the world who has control of over 40% of the world's economy, whereas Klein becomes the Underworld God who eliminated all his opponents and controlled the whole underworld.

But eventually, greed got over people's minds as they started coveting Alexander's wealth, and the same was for the underworld as people started banding together to capture the throne of the underworld. The world was plunged into chaos as both the beings started to lose their family and as their trusted ones backstabbed them. In the end, both of them died together in a planned plane crash as they met each other to make a business deal.

The fourth duel started in a world filled with human dominance with few sparse races scattered around the world. The being of light was born as Xavier the 9th prince of a small backward kingdom. While the being of darkness was born as Hayden the crown prince of one of the two major empires in the world. The being of light had to struggle against his brothers as the ninth in succession to the throne. He used his knowledge of a technologically advanced world to lead his territory and gain influence as he finally became the king of his kingdom after countless struggles. While Xavier struggled In his small kingdom,  Hayden grew up into the emperor of his kingdom as he used his battle sense from his past to brute through any obstacles placed in his path. Almost this time both the beings knew something external force was at play from their memories and to the present as they each had a vague idea of the other. Xavier thought the other being was born into one of the other kingdoms and losing pathetically was enough as he frantically tried to expand the borders of his kingdom. While Hayden thought the other being was in the other empire and sought to grow the strength of his empire.

The whole world soon plunged into chaos and war as every kingdom and empire started to war with each other. Amid this war, Hayden's army reached the border of Xavier's kingdom after a bitter struggle Xavier couldn't hold onto his throne as he lost his kingdom and throne as he was executed before Hayden. Only at the last moment of death did both meet their eyes as they felt the strange connection between them as everything else unraveled. Xavier mocked at himself for his fate, while Hayden had a wide grin on his face as he laughed at Xavier's misery. The fourth time also ended with the loss of being of light as the being of darkness eventually ruled the world.