Elf Tensei Kara no Cheat Kenkoku-ki - Chapter 10Book 4: -4: Compromise

Solver Keter, one of the Five Lunatics of Lawless City, regresses to when he was the illegitimate son of a doomed archery family.“If I regressed and couldn’t even save my family, I might as well go kill myself.”For my family? No, for my freedom!

“Obtaining the topmost degree of talent in sword arts in the world requires giving up 72 years of lifespan, which leaves you with only five more years of your life. At the same time, you will never be able to feel love, kinship, and friendship, and you’ll end up leading a lonely life until your death, unable to procreate, or to have any descendants.

“From now onwards, everything related to happiness in the human world shall no longer be of your concern. Are you willing to accept this?”

“Hahahaha, I’m already alone bereft of all support, my hopes dashed to pieces, shouldering only absolutely irreconcilable grudge and hatred, why would I disagree? Why would I not want it? I couldn’t ask for anything better!!”

His sword sweeps across the Divine Continent for seven days and nights, moving 90,000 miles through the starry skies, unhindered.

He slays saints and buddhas in Heaven, slaughters demons and devils in Hell, sweeping away all the grievances in his heart!

- Description from Novelupdates

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 boy born with the potential, so great that it threatend the world's powerhouses itself._____Born amidst chaos and tragedy, Azhrael, the son of the legendary Frost King and Celestial Witch, carries a burden no child should bear. Half of his soul was dormant into another world, while the other half was left sealed, hidden from the prying eyes of those who sought to destroy him.He was a child of immense potential—his very existence threatened gods and shook the balance of power in the world.However in the main story, Azhrael was only an “extra.” A mysterious beautiful boy with snow-white hair and dull grey eyes who exists in the shadow of others, bullied and beaten, unaware of the legacy he carries.That Is Until.