How can you make a weapon that acts as a subtractive item in-game?

I’d like to make a bastardised minecraft homage (Rip off) and i’d like to make guns subtract space from the environment and players (The latter is less important).

If the impact of the bullet was in the shape of a subtractive element that I make before hand to dig into the map.
I’d allso like to know how to import elements of the editor into the final game.

Hope you can help, i’d really like to see this feature in games.