The supporting character's harem is very normal - Chapter 303 Sakuth’s worries

In his previous life, Lin Mu was the top assassin on Earth. He accidentally traversed to the Eternal Immortal Realm, where, over the span of eight hundred years, he cultivated from an ordinary mortal to the realm of an Immortal Emperor.However, as he was undergoing the tribulation to become an Immortal Emperor, his enemies ambushed him and his Divine Soul drifted through the cosmic Chaos for several hundred years. Now he possesses a body which belongs to another man also named Lin Mu, a live-in son-in-law of the Qin Family in River City who was constantly mocked and humiliated.“Rest assured,” Lin Mu mutters. “Since I have taken your body, I will naturally avenge you.”

Living things really are ignorant – the greed to obtain the key to knowledge and the fundamentals of energy overpowers them. Little do they know that knowledge is full of lies and energy is the root of destruction. Us, mages, have mastered travelling through space and time. We are invincible, we can turn worlds into dust and you, mere ants, will be wiped out with no trace.

-Mage Adam

An A.I.(Artificial Intelligence) gets reincarnated into a world where he becomes a mage.

[No fixed CP + wear books + brain hole cool text + women disguised as men + group pet]

Gu Lan crossed over and became the cannon fodder of the original book disguised as a man, counterattacked the protagonist of the original book who slapped her face, and lived in a dormitory full of sickly beauties.

Until one day, she discovered that her roommates were villains from other horror novels. After discovering the secret, Gu Lan thought she would be killed, but her roommates all looked at her strangely… Contrasted with cute Zhengtai, sickly and beautiful boy, split personality school girl, cold and stern school bully, romantic and noble son who plays Shura every day field.

- Description from novelbuddy

For Marco, Lucas is his meek little brother. For the rest of the world, he is the menacing Ghost of Vermil.“Angels endow blessings. Demons sow curses.” A hundred years ago, angels and demons descended on earth. It is said they are still here.Annointed with potent holy power, Marco is set to join the Kingdom's Holy Army to fight off the demonic legion. But before that, he must confront the trail of blood and ash that points to Lucas's involvement with the dark side.As mysteries unfold and loyalties fracture, Marco is faced with the question: where does holiness end and damnation begin? If all lines are blurred and the fate of humanity is at stake, will he have enough resolve to strike down the brother he once swore to protect?