I Can Do Anything? - Chapter 43: To Win Is To Realise Your Flaws.

Song Yi found herself transmigrated into a novel, becoming the female protagonist of an old-school Mary Sue story.Gentle, kind, beautiful, and graceful, she was the unattainable ideal in everyone’s heart. The aloof top student fell from his pedestal for her sake, while the reclusive young man fought against his family for her.All of this sounded quite nice, but there was just one problem – this novel had a bad ending!!!

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

John sacrificed himself to protect Earth and resist the gods, only to be betrayed and killed by his best friend.To his surprise, after death, he was reborn just before the launch of the game “Gods Descend.”In this life, he vows not to let the tragedy repeat!Upon entering the game, John masters the power of reincarnation and unexpectedly awakens an SSS-level talent—“Plunder”!By killing monsters, he can plunder their attribute points; by killing boss-level elites, he can plunder their talents, skills, and special attributes.Killed a tusked wild boar: Physique +1Killed a bloodthirsty wolf: Speed +1Killed an elite boss: Gained 10 skill pointsKilled an epic boss: Gained 10 luck pointsKilled a legendary boss: Gained an S-level talent, Spell Combo...As John grows through killing, when the game merges with reality and the gods descend, they finally realize that there is an existence on Earth that they cannot provoke.John: “I will only make one move. If you survive, you may leave.”In the next second, the ultimate forbidden spell activates: Ragnarok!

This world has Fox Fairies, River Gods, Water Monsters, Great Demons and Cultivators who seek immortality.