I Ask You to Guard the Border and Defend the Island, but You Use a Slingshot to Fly?

Wang Feng traveled through the parallel world and became a soldier guarding the border and the island. Activate the system to gain the physique of a warrior king and a slingshot weapon! Just use the slingshot to shoot the target to get points, and the slingshot can be upgraded infinitely! Since then, Wang Feng has become the island war god guarding Kyushu! Are the Luzon fishermen who broke into Kyushu waters ineffective? Kill it with a slingshot! The Annan warship that broke into the Kyushu waters showed off its power? Blast it with a slingshot! Yingjiang's plane broke into the sea for reconnaissance, unscrupulously? See how Wang Feng uses the slingshot to hit the duster! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.