The supporting character's harem is very normal - Chapter 464 God’s Eyes

Regret filled Valyr as he witnessed Earth before him crumble into nothingness. Although he and the others had done everything they could, their efforts were all for naught as they stood powerless to stop the inevitable, causing billions upon billions of innocent lives to perish in the cold and unwelcoming darkness of space.

Indignant at the outcome, Valyr asked the heavens above to give him a second chance, a chance wherein he would make sure the inevitable didn’t happen. Though he knew that the likelihood of it happening was slim to none, surprisingly…

The heavens answered.

Opening his eyes, he swiftly found out his wish had been granted, in more ways than one at that. Not only was he brought back to the time where everything had yet to unfold, he was also reborn as an NPC in the game where everything started and everything ended.

The True Immersion VRMMORPG, Greater Beyond.

Utilizing his newfound advantages, in conjunction with his knowledge of the game and its various versions from his previous life, Valyr was going to make sure that what happened before wouldn’t happen again. And all of that began…

With him picking up the Blacksmith class.

I exist in the darkness, disappear under the bright light, and will eventually devour the sun and turn into the shadow of all things… Known by people as the indescribable terror of darkness; the king of shadows; the dark day; the existence of the shadow of the world , is still just a somewhat special high school student, facing a weird death game…

- Description from novelbuddy

Lin Wu was a university student that died after having one too many energy drinks and then reincarnated into the body of a worm. He awakens to find out that he now has a system, but even it doesn't have a clear idea of where they are.

He comes out of the ground and discoverers that he’s no longer in his previous world but rather in a cultivation world.

Witness Lin Wu’s journey as he worms his way to the heavens from a tiny worm crawling in the ground.

It was an enormous tsunami that completely covered the sky, and due to its dark water, the sun had been blocked out. A sense of despair ran through everybody as they looked towards the peaked wave quickly crashing down. But was I the only one who noticed the massive sea monster lurking towards the front of the wave? CRASH [Requirments Met] [System has been chosen] [Your god has been selected] [System Granted] [Poseidon System is being installed]