(SFM posters by me)
A replacement for sapper that allows spy to trade his ability to sabotage buildings for... well, spying.
CODENAME: POLAROID CAMERA
*** CLASS: SPY
*** SLOT: SAPPER
*** BASE: SAPPER
* Primary-Fire: Snap a photo of enemies and buildings in front of you, causing them to be highlighted on the screens of your allies for up to 5 seconds
+ Alt-Fire: Snap a flash photo of enemies in front of you, stunning them for up to 1 second
*** Flash photo has a 5-second cooldown
*** Using alt-fire causes you to drop disguise
- Enemies stunned with flash cannot be backstabbed or tranquilized
Note: In both cases, the detection hitbox should be assumed to be roughly the same size as Pyro's airblast)
By granting spy the ability to relay enemy positioning to his team, it empowers the entire team to better react and respond to whatever the enemy team is doing at that time. However, the duration of the reveal is short, meaning that the spy will need to use the Polaroid Camera regularly in order to keep feeding information.
In addition, the Polaroid Camera can also serve as a getaway tool (or a support tool, in the middle of a firefight) for spy by allowing you to take a flash photo (this shouldn't actually hit people with flashbangs, for those of you worrying about that), stunning enemies in front of you for a brief moment while you take the opportunity to slip away.
I've always been of the opinion that Spy's sapper slot has potential for gadgets more imaginative in usage than simply different flavors of anti-building tools, and this particular idea is one I hope will sound as decent to y'all as it does to me.

