Re:Zero Kara Hajimeru Isekai Seikatsu - Volume 4, Chapter 42 [The Value Of A Life]

After Reincarnating into Naruto World at the Warring State Era as an Uzumaki, Masahiko thought that he got a useless System. He lived for 48 years as a normal, below average Uzumaki Shinobi.

That changed when he finally knew how the system works the day of his 49th Birthday!

- Description from Novelupdates

Your prospects in life are determined by the elemental affinity for magic and streaks of the elements you possess.Logan Kress, a young boy who lost his parents to a plague, loses his elemental streak and affinity but gains something far more potent and potentially lethal in exchange.With his hair now pure white, he can wield magic like never before seen, opening a lot of opportunities for him but inciting the fury of beings infinitely more powerful than him.Read his journey for revenge as he hunts down those responsible for the plague, making allies and creating dangerous enemies along the way.

27-year-old Hisha, transmigrates into the body of a thousand-year-old overpowered supreme overlord who had everything at his disposal, except one–worthy companions by his side.

Hence, a tournament was held to choose the best out of the most beautiful, unique and strong women across the land.

These women don't follow the rule of coexisting women in a harem, they fight for the right to bed their lord and would stop at nothing but to use every opportunity to seduce, and fight on his behalf just to get his attention and favor.

Hisha never liked such a barbaric method of getting a companion.

'Why choose a few, if you can have them all?'

'If he can't have them all, he would try to work out coexisting the strongest for his pleasure and benefit.'

He realizes his 'Desire System' levels him up with every adoration gotten from his harem. The stronger they get, the higher his level and hold in his world.

As he continues to break his limits with the help of his harem, he finds out there are others that threaten his rule and the balance of his land.

'Let the tournament begin!'

The end of the world is coming, the world has undergone great changes, and everything has changed. Plants, animals, and even insects, as long as there are living things, have mutated.
Become more powerful, and even evolved supernatural abilities, such as chickens and ducks that can fly to the sky, such as cats and dogs that can breathe fire.
But only humans, without any obvious changes, seem to have fallen from the top of the food chain to the bottom of the food chain overnight.
Any creature that can open its mouth to eat can treat humans as food.
But fortunately, this world has not completely killed humans. Gradually, humans discovered that they had the ability to cultivate compatibility with other creatures.
As long as it has a high degree of compatibility with some powerful mutant creatures, it can be used for its own use to achieve the purpose of protecting itself.
Fang He is a person who is very compatible with mutant animals, but it is also because of his ability that he has changed from the strongest to the stupidest.
Fang He, who was reborn, said, “Hmph, this time…”

- Description from novelbuddy