THE COUNT’S YOUNGEST SON IS A PLAYER is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.thecountsyoungestsonisaplayer.com fastest updating comic site. The Summary is

[Activating closed beta system. Current number of users: 1.] Bae DoHyun lost his life because of the major guilds’ evil plan. He then possesed the main character in a game that’s still in its beta service. Reincarnated as Rich family’s youngest son, Raul. “I’ll take it all this time!” From Rank 1 player to the most powerful NPC, his new story begins.