Rebirth: Once Again With You - Chapter 505 Alliance

After getting forcefully reincarnated into a world of an otome game he has no clue about, the protagonist is then killed and brought back to life by the prideful villainess with one desire.

To rule the world.

As the ruthless girl’s Eternal Servant, how will he dodge the fate that the game system has in store for him?

As a boss with space plant abilities in the apocalypse, Lu Yao once traveled to the future, became the director of a nursery school that was about to close down, and became a rare animal human on the verge of extinction.
The food she made at random can cure the genetic disease of the cubs in the welfare home. She punched the cubs’ scum fathers and scum mothers, and kicked the remarried families who abandoned the cubs.
It is such a good kindergarten successor dean, who is attracted by that single cool imperial marshal!
Since then, the barrage in the live broadcast room has become:
Imperial Citizen A: Dean A, I really want to marry.
A certain big black dragon: Shut up! This is your marshal’s wife!
CP: Dean Lu Yao, who is extremely protective of short-sightedness and loves cubs, X the imperial marshal Helanjia who loves Shang Yunxi more than cubs
Brief: There are no bad cubs, only bad big ones.

- Description from novelbuddy

At the age of 12, Shen Yue accidentally fell into a pond while feeding fish. That’s when she realized that her parents were not her real parents, and her five brothers were not her real brothers either. She was just a fake heiress to the Shen family!

Knowing she was destined to lose everything, Shen Yue decided to just lie down and give up. If she was going to lose it all anyway, she might as well just lie down and relax.

“Big brother, is working at the company fun? Let me check it out,” she thought, wanting to enjoy the perks of being a Shen daughter while she still could. Those luxuries would be out of reach soon enough.

“Second brother, is acting fun? Let me give it a try,” she schemed. What? They pay you just to lie still like a corpse? This is a job she had to get!

“Third brother, is that gun realistic? Let me see,” she said, examining the firearm. Not bad, though the recoil is too strong. She’d need to find a smaller one to play with next time.

“Fourth brother, will the teachers be mad if I sneak into your research institute? Let me take a peek,” she plotted, eyeing her handsome professor. A little hugging wouldn’t hurt!

“Fifth brother, that medicine you’re working on smells nice. Mind if I try a little taste…” she asked casually before sampling it. Tastes good! But now my head feels itchy—I better not be growing a brain!

On the day the real heiress returned, Shen Yue’s five brothers shielded her behind them. “Dear sister, can we keep her with us? She’s a bit slow, it’d be dangerous for her out there alone.”

The true heiress scoffed coldly, masking her sly intentions beneath a guise of innocence.

But in the end, she realized this Shen Yue really was quite dim-witted. Oh well, might as well let her stay.

There are a total of seven sins, and a revelation is made to a young man named Alex that he is destined to become a demon lord, more especially a demon lord of sin called LUST.

It's not like he can change that and because he always knew something about himself was different—not in a physical sense, well, maybe a little—and not in a mental sense—but rather because he is thrown into a demonic war that compels him to accept his new reality.

He was only aware of a difference in himself. Relating to him and the ladies who are drawn to him... Well, it was more or less like he was a magnet in front of all the girls, and all the girls were drawn to him like a metal.