Dark Matter Ascension - Chapter 16 – Sometimes, one is greater than three

Upon meeting the girl who would become her adopted younger sister, the duke’s daughter Christina regained memories of her previous life. Through those memories, she learned that her new sister, Mishuli, was the heroine of a certain story. And though the story depicted a Christina who abused her sister, the real Christina turned into a siscon who spoiled Mishuli to no end.

A rich young master, a hedonist, has the Hedonist Sovereign System forced upon him. Follow this hedonist on his adventure of becoming a Hedonist Sovereign through doing real life quests, filled with action-packed battles and hilarious moments. A lazy and slothful hedonist doing exercise in the morning? A spoilt and self-entitled hedonist starting from the bottom as a salesperson? Watch as Qin Feng is changed by the Hedonist Sovereign System, inside and out!

- Description from Novelupdates

Vahn was an atypical youth. Due to a rare mutation, his blood had the potential to target and attack ailments within the human body. Touted as a universal cure, people had elevated his status above the norm and given him the classification "Panacea". In the media, he was hailed as a great hero who would usher in a new era or human wellness. However, behind the scenes things weren't so bright. Being a unique individual, Vahn spent his entire youth locked up in a lab with various scientists and research teams using his body and blood to perform endless amounts of experiments. The only solace in his suffering was the various anime and manga made available to him between experiments. He often imagined himself as the protagonist in a world of his own, finally in control of his own destiny. For years he nurtured this desire, until at the age of 14 he died when an organization had tried to kidnap him from the lab...

Her – a glutton without troubles or worries who crossed over and became a young fat chick with a deep vengefulness.