The idea I had was possibly a hologram gun for the Spy.
It would allow the spy to simulate that he is shooting a gun (Or meleeing) when disguised. The gun that would be visible to players would be the gun you last held before switching to the hologram gun.
Example: Disguised as Heavy and held out the nail gun last before switching to hologram gun. The visible gun to enemies would be a minigun.
The hologram gun would fire fake bullets and simulate gunfire from the held weapon. (Fire, bullets, swinging melee, etc). At the cost of either:
1 HP per fake shot fired.
or
-1 nail and bullet per fake shot fired.
or
-1 ammo of the gun you held before switching to hologram gun.
Some would drain faster than others. (When simulating a shotgun versus simulating a flamethrower)
My idea for what the spy would see is possibly a slightly see through version of the weapon it's simulating. What do you guys think?
If anyone could script this weapon for testing that would be fun too