The supporting character's harem is very normal - Chapter 77 Controlling the Thunder Element

The nuclear holocaust which caused the collapse of the Old Times on Earth should have wiped out all human life on the planet. Yes, the gods set up their beautiful Elysiums to provide sanctuaries for their chosen, but by all rights everyone outside the elysian lands should’ve perished long ago. Yet somehow, human life still managed to persist, even in the deadly, mutant-infested wastelands.

Cloudhawk was a young scavenger who dreamed of being as free as the hawks in the skies, yet seemed destined to live out his life scrounging for scraps in the wasteland ruins. Fate, however, is ever-fickle. A chance meeting with a ragtag group of mercenaries changed the trajectory of his life, bringing him into a world with mutants and metahumans, demonhunters and godslayers, and even gods and demons. Cloudhawk would find his own place in a world that was far greater than he had imagined, find his own path between the zealous light of Sumeru and the whispering darkness of the Abyss… and one day, he would find that even gods may fall.

In the 5th year of Konoha’s founding.The battle between Hashirama Senju and Madara Uchiha at the Valley of the End had come to a close.In order to treat his elder brother’s injuries, Tobirama Senju resurrected a medical ninja from ancient times, hoping that this individual could prevent the injuries from shortening his brother’s lifespan.This medical ninja’s name was Emiya Shigen.

Word went around that no one that had ever knocked on the esteemed Eleazar family’s doors seeking shelter were turned away.Fleeing the prince of Lustris no less, Arabella Sterling held out hope that those weren’t mere rumors as she crossed the border over to Umbraria, home to all creatures of the night. A land where noble blood like hers was a highly coveted delicacy.As such, she wasn’t turned away, but since the Eleazars ran no charity, Arabella was compelled to become the sole blood provider to the heir of the family in exchange for safety.Though never, in a million years, did she imagine that what had started as a simple trade off, could morph into a swirl of tangled passion when the cold and stoic vampire she served showed interest in the young woman beyond the crimson nectar coursing her veins.

I fell in love. Her name was Shirasaka Yukino. I could only look at her from a distance. However one day I heard that she already had a boyfriend. Even if I love her, I can’t have her. The devil sent me an invitation. I can make her mine!