You can create, summon, shape, manipulate, and utilize any kind of firearm with perfect skill. Be it primitive, modern, or even futuristic weaponry, each firearm is an extension of your power, seamlessly integrating into your hands as if an inherent part of your being.
From physical projectiles to liquid-based rounds, and even energy ammunition, you can summon and discharge them all with effortless precision. Without the worry about ever running out of ammunition.
You can only summon firearms directly into your hands. With your two hands filled, you are unable to summon additional weapons. Instead, you may instantly dismiss a firearm and summon another in its place.
You can't conjure ammunition or firearms capable of killing omnipotent beings on the get go, but would need considerable time and effort to manifest them (from decades to a century even, depending on how much you use and practice this power)