Moto Sekai Ichi'i no Sub-chara Ikusei Nikki - Chapter 80 Fallen Castle

Arakawa Kouki is reincarnated to a Japan with a different history than the Japan he knows with the memories of his previous life still intact. Kouki was discouraged, “Aren’t reincarnation stories supposed to be at some fantasy world filled with swords, magic and elves?!”

Duwei is born in this new world from Earth without making any sound, he does not cry, he just stares at the people around him. As he grows he does not speak and curses this new world in which he is forced to live.

His father a great general of insurance he must have aptitude for something, nevertheless he is not more than trash. Ignored by his family as the “ret*rded” heir.

This is the story of your journey to discover the truths of this world and use the knowledge of your past life to remove your title of ret*rd, even if you have to become a devil.

- Description from Novelupdates

After her rebirth, Rita vows not to repeat her past mistakes. This time, her first priority is to stop her brother, who is about to marry into the Lopez family, from participating in the initial game beta test. In her previous life, she was deceived by this scheming brother until her dying breath. It was only at the end that she realized she was merely a villain in a male-oriented novel about a live-in son-in-law, with all the malice and manipulation orchestrated by him behind the scenes. In this life, Rita decides to change the rules of the game. She will stay in the shadows and seize all the opportunities meant for the male and female leads. By participating in the beta test and re-selecting her abilities, she systematically dismantles the protagonists’ advantages, all while making them believe she’s on their side. Rita has no intention of harming innocent people, nor is she a selfless saint. In this game, she works with the authorities for mutual benefit, all to achieve her ultimate goal—becoming the true master of her fate.

Intelligence without ambition is like a bird without wings.