Ame no Hi no Iris - Chapter 4 - Letters Part 5

Going against the heavens, Tuoba Ye reincarnated. Body concealing Divine Root, hands holding Divine Talisman, possessing previous life’s experiences, from childhood, began cultivating the most difficult body refining method: Mythical Nine Transformations.

- Description from Novelupdates

Revere knowledge, pursue truth, control fire, command frost, manipulate lightning, ride storms, enslave the undead...Spreading ancient prophecies and curses, known as the wizard.“Immortal Phoenix Bloodline + Ancient [Eternal Life] Rune...”“After forty million sunsets, I shall finally attain immortality!”

their example, leading to continuous warfare! However, the aboriginal people of this otherworld who have been blinded by the aesthetics of violence! Rightnow! And in the future! Let me teach you what kind of mecha represents the romance of a man! Let me show you what kind of propulsion is the iron torrent! Let me instruct you what kind of weapon is the deterrence for peace (implied by “nuclear” here)! Let me! Teach you! What exactly is the air-to-ground cluster offensive and the all-round air, sea, and land strike!! Gentlemen! I, indeed, love war! But what I love even more is to stop war with war and bring about a prosperous future where the whole world is unified for thousands of generations! Unite all nations and subdue all races! When the whole world is united as one, it will last forever...

Leon, a man who tragically died of exhaustion due to his sister's otome game, unexpectedly finds himself reincarnated as a young aristocrat named Leon Bartfort. However, he soon realizes that he is not alone in this body. Another mysterious entity already resides there, its voice echoing in his mind.Who is this second consciousness? Is it a friend, an enemy, or something far more sinister? Will they be able to come to an agreement to share control over the body, or will a fierce struggle for dominance ensue? Or perhaps their interactions will lead to unforeseen consequences?Intrigued? Then start reading!