Are your rival LEGO® minifigures being bad and using poison gas? At first I was going to recommend that you give your troops these custom LEGO® gas mask/helmet combos, but on second thought, you should probably get yourself a custom LEGO® gas mask and investigate the source of that poison gas. Because, you know, minifigures can't actually move on their own. It's possible the poison gas came from someone cleaning with bleach and ammonia.
Minifigure is not included.
All Brick Warriors tiny toy weapons are made of solid ABS plastic, designed to be used with LEGO® toys. They cannot shoot bullets and cannot be made to fire bullets in any way.