The Forsaken Hero - Chapter 727: Another Mark

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.

“A cheat system? Do you take me for a fool? Nowadays, where can you find such a good thing falling into your lap? Scram from my head. Is this is new kind of fraud? Or is this a murderer training system of aliens that contains the ability of hypnotism?”

“No, I am the chaos that whispers from nothingness, the nightmare of all living beings in the Southern Ten Stars, the successor of the unparalleled God and… your elder sister.”

“…I only have a younger sister, I don’t have an elder sister!”

“No, you have one. I am an illegitimate daughter. It’s just that your dad didn’t inform you.”

- Description from Novelupdates

Sam Sanderson is envied by many for his job, however he himself didn't seem to like it much.

Due to his expertise in nanotechnology he was tasked with monitoring the state the Valkyries, humanity's strongest weapons who all just happen to be made into gorgeous females.

Forbidden from even touching any of them, Sam spends his days in agony watching flowers he couldn't hope to touch. However one day all of that seemed to change.