Rebrov has his own specialized weapon, which is indispensable to him, just like Gao Yang cannot be without his Blade of Satan, and Glolov cannot be without his machine gun.
Rebrov's weapon is actually stationery: compass, shooting elemental ruler, vernier caliper, command ruler, Earth's rotation correction chartboard, shooting correction chartboard, pencils, and erasers—these are his weapons.
He marked the locations of each artillery position on the map, then measured, corrected, and marked on the map bit by bit. After a long time, Rebrov finally marked his own position and wrote down lines of numbers that Gao Yang and the others couldn't understand next to it.
