The defense team failed? I turned into Jagula with my backhand

Description

Monsters are coming and the world is in danger. In order to deal with the monsters, humans form a defense team and build monster mechas.
Shen Yi, who came from time travel, chose to join the defense team in order to make money to protect his sister. In order to successfully pass the exam, Shen Yi trained hard, but failed for two consecutive years.
In the end, when he took the assessment in the third year, he successfully met the standard of the defense team. However, just when he was about to be admitted, Shen Yi's place was replaced by a candidate with a background, and he ultimately failed again. The helpless Shen Yi had no choice but to give up.
Just when Shen Yi was disappointed because of his own weakness, his desire for power summoned the system and successfully obtained the Jakula template and the dark ring.
Shen Yi can unlock monster cards and gain stronger power by continuously killing monsters. In this way, a ruthless monster hunter appears, and mankind is about to witness one world-destroying terrifying monster after another!
Are you fast? Are you faster than my Hyperjetton?
Powerful? Have you asked my Moge Orochi?
Intense firepower? Then let you see the full firepower of me, Gilbarris!
I only need to make a small move, and that's your limit!
As for the defense team? Even dogs won’t go there!