The Dark Swordsman Returns

A brief description of the manga The Dark Swordsman Returns:
On a battlefield at the brink of annihilation, unknown soldier Gray Lee had his chest pierced through—and he awaited death.
Only humanity’s strongest heroes—the Sword Saint, the Divine Archer, the Great Sage, and the Ultimate Shield—stood a chance against the “Liquidator,” a deadly enemy capable of burning down an entire continent in a single day.
Yet even those heroes fell, one by one, until all hope was lost…
…At least, that’s what it should’ve been.
“I got pierced through the heart, but I’m still alive?”
Gray did not die. Instead, he was guided by Chronos, the Master of Time. He was bestowed an unknown power, and with it he delivered a powerful blow to the Liquidator, shaking the threads of fate itself.
But just as a chance of victory appeared, another beam of light struck, Gray’s body reducing to nothing…
…and Chronos’s voice thundered, “I shall send you to the past. Save this world.”
The next thing Gray knew, he woke up in his hometown, which should long have been destroyed. It was the place he started his life of a loser—and was now the stage for his second chance.
“This time, I will survive!”
With the power to transcend time and his memories of the future, Gray sets out to become a warrior even stronger than the heroes.