The Strongest Man Died because of a Rock!

Takai Naoko, the strongest man alive, gave up everything he had to reach [The End]. Yet on his last steps he tripped on a mere pebble on his way! It broken his concentration, and undid his spell, as the [Guardians of the End], which previously couldn’t scratch Naoko, preyed on his flesh and ultimately killed Naoko. However, something sent him back in time, giving him another chance...