The supporting character's harem is very normal - Chapter 389 Have you seen enough?

“After every fire, ants survive.”

…

Mysterious anomalous biological metals have polluted the world, and the world has undergone tremendous changes. Metal sickness is like a key that opens the door to evolution. Under the tide of evolution, there are no innocents.

The choice is up to you, do you want to be the surviving ants after the fire, or do you want to risk your life, step on the glorious long steps to the gods, and glimpse the supreme glory of the mother goddess?

…

Touch the totem in your heart, follow the inspiration, and step on the long steps of ascending to God:

[Amphibians] → [Atlantic Glory] → [Ningen]…

[Eight Arms] → [Nightmare in the Sea] → [Deep Divers]…

[Eagle Eye] → [Owl Ghost of the Night] → [Jersey Demon]…

[Living Dead] → [Grave Digger] → [Death Ferryman]…

…

“On that day, the world was polluted, and I was the source of pollution. Human desires are endless, desire is the best food on the way to evolution, and I am the embodiment of desire.”

– Joe Tour.

- Description from novelbuddy

“Reincarnated into the World of Magic as a demon, the last thing Davis expected was to grow up right amidst the arms of angels. Ever since the group of philanthropic angels took pity on his miserable birth and adopted him, Davis has been forced to keep his evil identity a secret while he signed in to the system.

“”Ding! The Host has signed in at Angel’s Pond, ‘The Saint’s Halo’ is rewarded!””

“”Ding! Devil’s blood activated. Sign in error. ‘The Devil’s Curse’ is additionally rewarded!””

“”Ding! The Host has signed in at God’s Throne, ‘Gold’s Holy Axe’ is rewarded!””

“”Ding! Devil’s blood activated. Sign in error. ‘The Devil’s Manifistation’ is additionally rewarded!””

After a thousand years of quietly signing into places in the City of Angels and being rewarded with double the rewards, Davis’s true identity finally came to light! Now as a true Devil, Davis had both the world of angels and demons surrendering at his feet!”

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.

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.