MTL - Manga Guidebook - Chapter 44 fail?

Humanity has been gradually transported to the Abyss by a bored god to compete against other races and monsters.The problem is… humanity failed. In a last desperate push the strongest survivors chose a comrade to travel as far as possible back in time.

He Lang died by his own hands for the sake of his imperial younger brother’s ambition, whom he loved. He was offered to be reborn in exchange for giving up his past romantic feelings. Reborn without the burden of his romantic feelings, he brings with him a manual to new worlds. He wholeheartedly followed the instructions of the manual to complete the tasks, not knowing that the originally slag gong was blackening…
He pleaded to his affectionate Emperor brother to release him, he pleaded to the paranoid prisoner next door, but until the end he remained baffled.
In the end, he discovered that the full name of the manual was – “Slag Shou Cultivating Manual”
Σ (っ ° ° °;) っ!

- Description from Novelupdates

A thousand years ago, the Great Calamity struck Earth. Countless rifts tore through reality, opening portals between the Demon Realm and the Human World. Overrun by monsters, humanity was on the brink of extinction. But at its darkest hour, something miraculous happened—those who died returned, awakening strange new powers that allowed them to fight back.Vale knew that story well. Maybe that's why he wasn't surprised when he heard the voice of the system speak to him.[ Congratulations! You have died. ][ Your First Trial of Death begins now. ]What truly shocked him, however, was the question burning in his mind:“Who would dare to assassinate the Second Prince of Verythmia?”

Eric Maddox, a 70-year-old American retired football coach once hailed for his tactical brilliance, now forgotten by time—closes his eyes for what he believes is a normal nap in his quiet Florida retirement home.But when he opens them, he's not staring at ceiling tiles, instead, he's on a touchline.Wearing boots in the rain.With players running on the pitch, fans jeering behind barriers, and the smell of cheap turf pellets in the air.“What the hell is this?”He’s twenty-five again, but it’s not Earth. It’s a world where football reigns supreme. A world where the sport is religion, its practitioners, deities in cleats. Coaches are revered, players are worshipped, and even the kit man gets treated like royalty.But there's one catch: none of it is familiar. The clubs, the players, the leagues, the competitions, and even the currency—they're all different. Alien. Like waking up in a dream where the rules are the same, but the language is foreign.As if that wasn’t enough, the body he’s now in? A youth coach with a laughable win record, a looming divorce, and a measly fifty thousand in the bank that his ex-wife is fighting tooth and nail to take. All of it.Just when the spiral seems inevitable, a monotone chime pierces the noise.[Initiating Golden Finger…][…45%… 75%… 100%][System Integration Complete.][Welcome, host. You are now bound to the Pro Manager System. Objective: Dominate the Football World. A new era begins]From washed-up has-been to chosen one of destiny, Eric Maddox is about to trade arthritis pills for tactical boards, and shuffleboard for Prestigious Cup glory.Because in this world, tactics are power.And on this touchline, he’s about to become a god.