Sokushi to Hametsu no Saijaku Majutsushi summary:
Arc and Lean are aspiring adventurers. Upon appraisal, Lean is revealed to be on the level of a hero, with the level cap of 30 and the skills [Sacred Magic] and [The Goddess's Blessing]! However, Arc has an instant death magic with a level cap of... 1?!
With his instant death magic, he'll becomes embroiled in a national crisis that shakes the world!