Solo Leveling: World´s End

Many Worlds in a fiction show a surreal World of Mystery. May it be Magic or other unnatural phenomena. What is seen in them is a Protagonist that harvests the Fate of that said World as a Child of Destiny. Sometimes Fate plays the cruelest of tricks at someone. When two worlds clash together in the very time of their collapse, what will await a simple man if he gets thrown into action that he never before experienced?