BTTH: From Genius to Invincible - Chapter 7 - : Alchemy

Alex Walker was a living legend in the game. Some argue that he was the best midfielder in the world back in his prime... The same people would tell you flat out that he was the worst manager in the world.Three relegations in his first five years... erratic relationships with his players and tens of millions of money spent on unknown players with little to no identity.After suffering a heart-attack on the back of yet another relegation, Alex Walker wakes up to something strange.[Ding! Coaching system has been awakened!]

Transform into Divine Dragon and dominate the world!
He is the only Divine Dragon in the sea who founded an underwater Dragon Palace.
With Crawfish Soldiers and Crab Generals as his followers, wild sharks and gigantic octopuses as his subordinates, he is the dragon that rules the city.

- Description from Novelupdates

Adam begins as an ordinary high school student whose life is shattered when his parents vanish. The police later declare their deaths a double suicide, a conclusion Adam refuses to accept.His persistent quest for a real investigation leads him into a dark conspiracy when two corrupt police officers kidnap, torture, and murder him. In his final moments, they reveal his parents were also murdered by an untouchable, powerful entity.Instead of dying permanently, Adam awakens with a new reality: he has been granted a 'System' and the supernatural ability of 'Return by Death,' forcing him to relive his final days.Confused, Adam tries to confide in his trusted teacher, only to be betrayed and killed once again. This time, he learns the staggering reason for his persecution: a $100 million bounty has been placed on his head, making everyone a potential enemy.Dying again and again is horrible. The pain changes Adam completely. The sad, normal boy he once was is gone. He becomes a cold and ruthless killer. He trusts no one. If he even suspects someone might be a threat, he will kill them without a second thought. His only goals are to survive this deadly game and get revenge for his parents.During one of his loops, while investigating, Adam crosses paths with a female classmate being tormented by bullies. He saves her in a moment of detached action and quickly forgets the incident, focused only on his own war. For the girl, however, this act of salvation ignites an intense and devoted love.This devotion becomes a tragic and recurring element in his nightmare. The girl, willing to do anything for him, repeatedly throws herself in harm's way to protect him, often dying in his place across multiple loops.Adam is now trapped not only in a fight against a vast conspiracy but also in a cycle of watching an innocent person die for him, further cementing his transformation into a hardened protagonist who has lost nearly everything, including his own humanity.

He is an undead who is devoid of all humanity, he is the one and only supreme overlord, he is a man who has severe mysophobia.

There are many people who try to act cool in front of him, whatever soldier king, assassin, system user, transmigrator, reincarnator, the strong returning, the strong coming down from the mountain, person coming back from the immortal world, reincarnation of the devil king, immortal emperor possessing someone’s body, and so on, all of them do not know what will happen next

- Description from Novelupdates