회귀 후 마법 천재가 되었다 (Associated Names)

Randel, a talentless mercenary mage, on the brink of death in a mysterious ruin, heard the artifact say: “I will save you. In exchange for 10,000 lives―” “Get lost.” Thwack! He smashed the ancient artifact spouting nonsense and returned to 30 years ago. And then … the casting time for magic became 1 second.