The Unwanted: Starting by Saving the Entire Yuling Tribe

Harem + a protagonist who isn't blindly arrogant + System + making every dream come true + lots of original content + sweet romance + alternate history + altered timeline + stronger power-scaling + daily life woven into the main plot.

Li Yutian transmigrates into the world of The Bad Kids and arrives one month before the Yuling Tribe is massacred.

A Bad Person and Diguixing? On equal footing with Yuan Tiangang, or even his disciple?

He even has a beautiful female disciple of his own.

Oh, in that case, never mind.

Li Yutian awakens the System and from the start gets the Season Seven peak Li Xingyun template, along with an elixir of immortality!

In that case...

I'll save the princess, and I'll save the entire Yuling Tribe too.

I'll open a trade route between Mobei and the Central Plains and bring peace to the people.

I'll save Qiao'er and Shiji, and Li Chunfeng too!

I'll cite the classics, argue my case, and use my unmatched eloquence to persuade him to take the elixir of immortality, just to make Yuan Tiangang happy.

I'll help Xuanzong usher in the Kaiyuan Era of Prosperity, and do everything I can to comfort the people and earn a flood of prestige during the rebellion.

I'll put down the An Lushan Rebellion and suppress Huang Chao's uprising.

Emperor Xizong thinks nothing of Huang Chao's rebellion? Then he'll have to step down and make way for the wise Emperor Zhaozong.

What good is an emperor? Can he give us food when the people are suffering?

We'd be better off relying on Prime Minister Li...

Along the way to making everyone's dreams come true, I'll take in all the beauties and spend eternity with them.

But gradually, this world starts to go wrong.

The mysterious Jiugai, never explained in the show, unleash tremendous fighting power. The world's power scale skyrockets, and many powerful living dead appear out of nowhere.

They seem to have some connection to the System...

[In the early stages, the protagonist is nearly invincible. He'll generally get dragged into a tough fight, but will just barely win.]