So, a player of mine plays a minor talent character. He is a detective with psychometry.
To even the playfield, he would like to have a gun with special ammunition to combat the supernatural.
Here is what I have come up ith. First, he would create a stunt for his Investigation skill that allows him to role investigation to find out the Catch of the monster he is fighting. I'd set the difficulty of the role depending on how rare the mosnter is etc. This would allow him to create an aspect pertaining to him knowing the Catch of his opponent.
Then his gun would mechanically count as an IoP that cost him 1 refresh that has a spin on the SotC ability: All Creatures Are Equal Before God. Something like this, "if you created an aspect about investigating the catch of a supernatural creature you can pay 1fp to activate this power. For the duration of the scene, your bullets count as the Catch to the supernatural beings power".
Now, this is how I imagine it to work mechanically. In-game this is explained as him investigating the catch and preparing the bullets beforehand. So the gun isn't really magical hence the "" in the title, it's just him doing prep work and paying a fp to activate it.
Is this a good way to frame it in the rules or am I overthinking this? Is it balanced or to op, not op enough?