MTL - Doomsday Begins with a Nightmare - Chapter 89 New order? it's up to you

Childhood sweethearts.
The most popular person in school is my childhood sweetheart.

- Description from Novelupdates

A thousand-year dynasty would inevitably face decay, and a hundred-year noble family would eventually return to dust.What in this world could last forever?Was it an Immortal Body, tempered a thousand times, or the Martial Arts will, in Heart Unity with heaven and earth?Chen Mu came to this world, his sword in hand, and when he turned back at dusk, countless heroes and millennium-old Demons had all turned to dust, leaving only one person on the road paved with yellow sand.

Luo Zheng is at the bottom of the Luo Clan hierarchy, despite his family being the founders of a power refining technique that could instantly defeat any opponent.

One night, enraged by unfair treatment from a family steward, Luo Zheng burns the family records. In doing so, the hidden magic in the book engulfs him and Luo Zheng becomes a new skilled fighter. Fleeing his home and despicable clan, Luo Zheng must learn to harness his powers to rescue his younger sister while his own cousins are on his pursuit.

- Description from Novelupdates

Yuan Luoyi felt like she was a little hamster in a pit of snakes, with her family full of crazy villains, yet as the fake heiress she still focused on slacking off.

Dad was an arms dealer, Mom an ace assassin.

Eldest brother, business world’s killing god, with proxy syndrome.

Second brother, cold-blooded lawyer, zero moral sense.

Third brother, addicted to killing, born with antisocial personality.

Fourth brother, evil celebrity, who trained fans into believers.

Fifth brother, genius scholar, loves those pure white bones.

Yuan Luoyi didn’t know that because of her birth, the world gained five more brothers, not five more lunatics.

Those greedy villains also didn’t know, the one they wanted to kill was not an ordinary girl, but the most beloved little sister of five crazy bastard brothers.

The female lead has 99 lifetimes of memories, a system, harem darling + suspense, happy ending.