Ochikobore Kenja wa UR Skill Keishousha de Nariagaru

Ochikobore Kenja wa UR Skill Keishousha de Nariagaru summary:

In a world where dungeons connected to another world have appeared, people who awaken to mysterious powers and defeat monsters for a living are called adventurers.
Yuto Kirishima draws the jackpot job of Sage, but for some reason, his magic power is zero! He is looked down upon as the weakest Sage who can't attack. Ultimately, he is abandoned by his companions and used as a sacrifice. Just then, a mysterious choice appears before him.
"Do you want to perform this action?"
When he answers, his abilities awaken and the UR skill activates. This skill allows him to use the techniques of past sages!
With the strongest skill in hand, the story of his struggle to rise as the strongest adventurer begins!