Tsuihou Sareta Fuyo Jutsushi, Saikyou no Jouzan Fuyo de Nariagaru ~Boku no Fuyo Jutsu wa +20 Janaku x20 Nandesu~

This is the tale of a young man who dreams of conquering a S-rank dungeon to fulfill a promise he made with his childhood friend with the help of his Multiplication Enhancement Magic. Desmond, a D-rank adventurer who can only use basic enhancement magic, has a secret. Unlike normal enhancement spells that increase stats through addition, his ability is based on multiplication. Not +20, but x20! However, his party fails to understand his ability's true power and banishes him from the party. Just then, his childhood friend Cynthia, a S-Rank adventurer, appears before him. Accepting her offer, Desmond joins the top-tier clan Chevalier Garden. With his enhancement magic, he begins taking down fearsome dungeon bosses, clearing dungeons at impossible speeds, and achieving success.