What will happen to the military if monsters and magic really exist?

In 2030, 25 years after the appearance of the inter-dimensional portal, the world had completely changed. Intelligent beings from other worlds had blended with humans. At the same time, otherworldly monsters had been crawling out to attack the earth. Their attempt nevertheless could be warded off by the military through a special area called the Red Zone. Monsters pose no threat to modern weaponry because they were just biological creatures, not deus ex machina BS that could only be fought in medieval-style combat. They had eventually became new resources that changed the face of the world. Primarily the energy crystals that had ended the era of fossil fuels. Their existence was unavoidable. Unfortunately, all the wealth of the Monster Era was controlled by a small group of humans called the walker.

No fantasy story would be complete without the chosen one, isn't it?

Walkers saw themselves as exclusive, superior humans with the power of the system. They had MMORPG-like things with leveling and magical clince that everyone knew about. They were the only ones who could pass through inter-dimensional portals to other worlds, as well as the only ones who could process monster carcasses, especially energy crystals. They ruled the world with their wealth and popularity. Walker's existence was so absolute that the leaders of countries around the world could not do anything no matter how bad Walker's behavior was, particularly the Walker Association, which manages Walker's needs. In the end, the association kept crossing the line until the entire government secretly ran a secret project against them.

The Military Walker Project, the project that made Sukma Diki, the protagonist, begin his new life as an elite soldier in 28/Burmon Company.

Diki was a terrible soldier who had been the test subject for the military walker project. He was chosen by the government not because he was a walker but because he had a little secret known to the intelligence agency. Diki was revealed to be an intelligent race from another world who disguised himself as a human in order to study Earth's life. He despised walkers since their crimes were more heinous in his homeland. There were no rules like on Earth on other worlds, and walkers were regarded as heroes, so they treated otherworldly beings as mere NPCs. And on top of their ambition, Walker destroyed Valora Kingdom, a beautiful place that was none other than Diki's homeland.

The gorgeous place had been burned by fire. Valora's civilization was on the verge of extinction. Diki returned to his world after seven years on Earth and brought his modern science to rebuild his nation, which had been decimated by the walkers. Of course, he made them pay with his combat skills as an elite troop operator.

The war between Magic vs Modern armament had begun.