Armor Hero: Saved by the Shadow Emperor from the Start

What happens when an overworked corporate drone transmigrates to a world where anyone has a chance to become an Armor? The protagonist, Sun Zihan, transmigrates to a world where anyone has a chance to become an Armor. Since he didn't transmigrate into someone else's body, he has no special talent whatsoever and is completely ordinary. After being constantly egged on by others, he decides to sneak into the Demon Capital and steal one of the first Armor Summoners to appear. From the very beginning, the first Armor Summoners have required no special talent to use. But something goes wrong on this trip. (This book has a slow start, so don't rush it. There are some goofy scenes, so please don't read if that's not your thing.) No heroine + invincible protagonist + villain protagonist + decisive and ruthless (It may lean dark at times. Since the protagonist is invincible from the start, there aren't many quest rewards in the early chapters.)