I Just Turned 80 and the System Asked Me to Save the World

At the beginning, he dressed like a bad old man, and the rich man's son celebrated his 80th birthday? Ye Tian was a little confused! Fortunately, the system came and Ye Tian was saved. Just... Why does the system say that a global mutation is about to occur? Do you want him to save the world? From then on, he wore a hurdle vest, stepped on beanie shoes, and held a toy water gun, fighting monsters everywhere! Fight monsters all the way to upgrade, pass five levels and kill six generals! It makes those with supernatural powers admire them and makes them fall to the ground, but also makes the monsters fearful. Soon after, Ye Tian has become the strongest grandfather recognized by the world!