Modern weaponry in fantasy world

Kevin was a famous ego shooter in the VR MMORPG FPS game "Shooting Star". As he was clearing a quest in SS, he was dragged into a fantasy world. Now he had to clear the nine Tower of Velvet within five years. If not, his death is guaranteed. Fortunately, he had his battle dolls, also a vast weapon arsenal with him. But several fractions like theOrder of Inquisitorswanted to eliminate him due to lack of mana. Also, influential leaders from various underground groups and powerful kings from empires and kingdoms show a vast interest in Kevin's weapons, which can operate without mana. How will Kevin face this kind of obstacle and survive?