Harry Potter and the Dovahkiin - Chapter 66: Vindicated

Within the virtual world of “Avalon Online”, Finn, or otherwise known as “Echo” within the game, was one of its greatest players. After logging off from a long session, however, he notices something awry outside of his apartment.The streets were flooded with chaos, screams echo through the night, and hell is loot loose. Monsters from Avalon Online are running through the streets, wrecking havoc. In the midst of this hellish awakening, Finn is greeted with the one gift bestowed to humanity in this dark hour:[...Assessing life experience…][Assessment Complete][Name: Finn Thorne][Age: 20][Designated Class: Assassin][Starting Level: 5][A [Legacy System] has been bestowed to you for your accomplishments within Avalon.][Assimilation System Awakened.]In this twisted turn, as the world as it was once known is gone with the arrival of magic and monsters, the remnants of humanity must level up if they wish to survive.Finn is left in this dark, hopeless apocalypse, using his own experience from Avalon Online to best survive what seems to be an impossible task.

As the last abyssal demon in the world, Wen Long was pulled into various worlds to do tasks by a guy who claimed to be a system. The goal of her mission was to save those villains who had been blackened for various reasons…

- Description from Novelupdates

Lu Xiaoran has traveled to a fantasy world and received a system, but the useless system has not been activated for a long time. Lu Xiaoran, who had no choice, could only cultivate in a low-key manner and grow steadily. However, after Lu Xiaoran had become the strongest existence in the entire sect, the dog system suddenly activated.

[The return of the Great Holy Spirit, blood boiling! 】 The father was killed, the family wealth was taken, all the hands and feet were interrupted, and the revenge flame was ignited, and the Qitian Dasheng inheritance was obtained. Since then, the rise of the sky, God blocked the killing, the Buddha blocked the Buddha! Qin Feng wore a gold armor and held a hand of the sea god: “I want this world for thirty-six days, and I will return to the big holy flag!”

- Description from Fpzw (Translated)