Returnee of the End: Second Chance of the Strongest Speedrunner

One day, the world ends. Earth is completely destroyed and ten thousand survivors are selected by a mysterious voice to undergo the 'Trial of 100 Worlds'. The voice tells them to clear each of the worlds, and only then will they save the world. Hunter, a former professional game speedrunner, takes to the game system of the Trial with ease, becoming the first to ever reach level 100 in the Trial. But when Hunter is killed, humanity loses its only hope and falls. Hunter is sent back to the past, becoming reborn as a returnee to when he first stepped foot into the Trials. The strongest returnee now climbs the worlds of the Trial once more. To reach the top of the 100 worlds. To reach the Zenith. To stop the End.