The Tale of the Weakest Hunter

This is a story that takes place in a world that is physically identical to our own except for three differences: gates, monsters, and hunters. Gates are portals to other dimensions that open and let monsters out into our world, but they also act as a doorway to their world allowing those who awaken as hunters to fight them. Monsters are various creatures that live in these gates ranging from goblins and golems to vampires and dragons. Hunters are humans who have awoken special abilities in the form of a stat window, class, rank, and unique abilities depending on your class, rank, and stats. These classes range from bandits to swordsmen to archers to even mages. The ranks go by letters and they follow as: F-E-D-C-B-A-S-S-S-SSS-National. Stats take the form of numbers in these categories: Strength, Agility, Endurance, Mana, Intelligence, and Vitality. Each rank has a stat cap and this can only be overcome by obtaining the next rank by slaying a monster of that rank. You are a veteran hunter who has somehow never ranked up or increased their statpoints. When the story starts you are adventuring in a dungeon and a mutation occurs causing a much higher-level boss to spawn killing you. But you are revived and sent back in time ten years ago, giving you a second chance and the power of knowledge and experience as a ten-year hunter while everyone else is new to the game again.