DxD: Matsuda? - Chapter 9: The VP Loves Me?

A mecha otaku is reincarnated into another world as Ernesti Echevalier (Eru). In this world there exist huge humanoid weapons known as Silhouette Knight. Dreaming of piloting those robots, Eru, with childhood friends, Archid Walter and Adeltrud Walter: together they will aim to become a Knight Runner, pilot of Silhoutte Knight.

Noah Black, a young man with an abusive father who had no opportunities in life, condemned to live a substandard life because of his father's mistakes.

Noah Black from the parallel universe, a marginalized, obese young man with social problems and a somewhat problematic but loving family, but who couldn't live long because of the mistakes he made.

When Noah 1's mind enters Noah 2's body with a Gamer System, the path to becoming the biggest superstar in this new world begins.

Is that body fat? I work out with the system and in a few days I have the perfect body!

Is my family poor? With my knowledge of my other world, I can make easy money!

Is this face ugly? With System I can look beautiful without plastic surgery!

Do I sing badly? In a few days, the System will transform my voice into the voice of an angel.

Do I act badly? In a few days, the System will make me an Oscar-worthy actor.

I can learn anything I want!

“Rising to the top was like a game, and now I have become the Final Boss of the entire world!” -Noah Black.

Miguel transmigrated into the Wild Beast World in the body of a useless teen with the same name as himself after he was betrayed by his disciple, the Harem Emperor, for a knowledge and universal secret that he recently uncovered.In the Wild Beast World, humans could contract Wild Beasts through their Summoning Grimoire, a mysterious book that fated individuals can awaken at the age of 18.In this world of summons and beasts, Miguel awakened with the Beauty Sign-In System, which allowed him to contract legendary beauties as long as he signed in at a specific location.On his first sign-in, he received the Holy Daughter of the Red Family, the Fiery Empress of Legend.Using the Wild Beast World and the Sign-in System as a starting point, Miguel swore to return to the Immortal Cultivation World and settle scores with the Harem Emperor once and for all.Follow Miguel's journey as he reaches for the apex, becoming a legendary figure in all worlds.

The notorious imperial court lackey and the meritorious military general were well-known for their mutual dislike, a pair of arch-enemies set in stone. Who could have foreseen the unexpected change in the winds of heaven: the general injured on the battlefield, both legs disabled, and even forced by the emperor to marry his nemesis.  

With one marriage edict, two people with mutual hostility are forced to marry and live under the same roof. Yet after these long days together, they come to the realization that this fellow is not truly devoid of any saving grace/unattainable and high out of reach.

- Description from Novelupdates