The supporting character's harem is very normal - Chapter 474 Peace before the Storm

An unexpected discovery in Machu Picchu has transported a young professional thief from Earth to a world filled with mystical powers and evil plots. With his beloved teacher and best friend killed during the calamity, his only goal is to become stronger, so that he can take revenge for them.This is a novel filled with politics, the struggle for power, evil beauties, and of course, Divine Immortals.

- Description from Novelupdates

When a boy in a medieval fantasy world wakes up with the memories of his past life, he discovers a secret buried deep within his mind—a highly advanced AI companion. This AI, a relic of his previous existence, holds the knowledge of a futuristic world filled with technology, science, and innovation.Armed with this unprecedented advantage, the boy embarks on an extraordinary journey to transform his medieval surroundings into a thriving futuristic utopia. From reinventing agriculture to creating advanced cities, he introduces ideas far beyond the comprehension of his peers. But his vision isn't without challenges—power-hungry nobles, skeptical commoners, and ancient magical forces stand in his way.

Xia Lian, a 21st century military doctor died in an explosion and found herself transmigrated to the body a 12 year girl. Her mother died and her father abandoned her and her little brother for another woman.

In the early world of immortal cultivation, there was no physical cultivation among immortal cultivators. And a top bodybuilder who came from the earth has opened up a new path here and became the ancestor of physical training.

- Description from novelbuddy