In This Life, The Greatest Star In The Universe - Chapter 25:

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

The narrative follows a gamer who, after selecting the “Awakened Cinder” class in the game Fractured Dawn, finds himself transported into the game's world. However, this version of the game is devoid of its usual interfaces—no UI, no tutorials, and no second chances. Each death strips away a part of his memories and identity, immersing him deeper into a perilous reality.The protagonist, now known as Riven, must navigate the treacherous Witherlands, confronting formidable foes like the Gravemare and Dreamborn Horrors, while uncovering the mysteries of Emberlight, Grace, and Cindershrines. His journey is one of survival, self-discovery, and challenging the very fabric of this fractured world.

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...

At the age of 15, He Jin found himself a “husband” in an online game, their love was filled with loving affection and sweetness. However, because his study was being interfered with, his parent cut off the internet, he didn’t even have a chance to say goodbye and had to disappear from the game.