The supporting character's harem is very normal - Chapter 53 Lathel vs Alec (1)

Traversing to a parallel World, Shinji Kamihara discovers a mysterious notebook called the 'Chronicles Of Urban Legends'.By writing urban legends in its pages, he can bring them to life in the real world. In this Japan, many of the urban legends from his previous life are absent—Hanako-san of the Restroom, Hell Girl, Sadako’s videotape, the Eight-Foot Woman, Mary’s phone call, the Seiryūji Tunnel, the Gaze from the Cracks, Tengu Elementary…“Let me unleash a pandemonium of Monsters and Ghosts upon this World!”

Bai Xiaocheng was hit by 200 million, really 200 million, one? Pan Kochang?

- Description from novelbuddy

Lu Xun was beheading demons and exterminating evil, not knowing what a worthy opponent was. On that day, Lu Xun found himself defenseless as he was beaten by a powerful female demon, unable to fight back, and was forced into marriage with a young demoness.“A real man should not dwell under the influence of demons for too long!”With impassioned words, Lu Xun successfully married into the demon clan. The young demoness was a 400-year-old golden snake, cold as ice, and arrogant. The powerful female demon was a thousand-year-old white snake, mature and charming, with captivating beauty. The little female demon was a 200-year-old fox, mischievous and adorable, full of liveliness.“Something’s not right!”“These female demons are not normal!”However, Lu Xun gradually discovered that not only were these female demons suspicious, but there were even more peculiar things happening outside!

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates