The Monster Monarch System - Chapter 28: Monster Within The Silence

She, a modern hidden ghost leader of an organization which gathered insane prodigies proficient in the various differing skill-sets. Highly skilled in medicine and poison, executes covert assassinations, viewed as insane and demonic in the eyes of people of the world. Killed in an accident, and reborn into the body of a disfigured young girl.

What? Face disfigured, identity stolen? A return to the family dim and hopeless? Her identity can be given up, her family can be forgone, but as for the one who harmed her predecessor who inhabited this same body, if she didn’t at least make them scream in unimaginable agony and throw them into a state of wretchedness, how could she live up to her demonic reputation? Endless turmoil ensues and it’s a battle to dominate over all! See how she shook the world dressed in a suit of red, her sword up against the dominant powers that rocked the Heavens! Her name spread across the seas, shocking the earth!

- Description from Novelupdates

Synopsis: System Awakening in Elegia – The System Activates!Jessie never imagined his life would end so abruptly—only to begin again in the world of One Piece. Reincarnated in Elegia, the Land of Music, he finds himself in a peaceful yet melancholic scene. Before him lies a motionless Uta, cradled gently in the arms of the infamous Red-Haired Shanks. Jessie, still powerless and stunned, can only watch as her life slowly fades.Frustrated by his helplessness and lack of strength, he suddenly hears a sound echo in his mind:[DING!][“Supreme Check-In System initializing... 1%... 100% complete.”]A voice rings out in his head, calm and mechanical—but filled with promise. The Supreme Check-In System has fully loaded. Its ability? Every time Jessie sets foot on a new island, he receives a heaven-defying reward.Stunned and thrilled, Jessie asks, “Do I have a novice reward?”[DING!][“Yes. Claim with your mind.”]Without hesitation, he shouts in his thoughts, “CLAIM!”DING![Congratulations! You have received the Sword God Inheritance (MAX)][Congratulations! You have received the 3-Domineering System (MAX)][Congratulations! You have received the One Fruit: Supreme Resurrection System]Eyes wide and heart pounding, Jessie grins with uncontrollable joy.“System, I love you so much! You’re the best! Hahaha!”With unimaginable power now coursing through him, Jessie sets his sights on rewriting destiny—starting with saving Uta, and eventually challenging the very balance of the seas!

However, he did not know that he was not raising just a harmless pet, but a biological weapon secretly made by the government… a real monster.

As a former librarian, Rand felt that he had been living an ordinary life, the one that he had reclaimed unconsciously every single day.

Recently, he has been a little upset because the pet fish he accidently brought home to raised seems to have undergo some strange changes

Well, it turned into a merman.

- Description from Novelupdates

An unnamed 34-year-old Japanese NEET is evicted from his home following his parents' death.

Upon some self-introspection, he concludes that his life was ultimately pointless.

Walking down a street he intercepts a speeding truck heading towards a group of teenagers, in an attempt to do something meaningful for once in his life he manages to pull one of them out of harm's way before getting himself in the way of the truck and dying.

Awakening in a baby's body, he realizes he has been reincarnated in a world of sword and sorcery.

He resolves to become successful in his new life, discarding his past identity for his new life as Rudeus Greyrat.