Disclaimer – TF2 belongs to Valve, not me. I'm not profiting from my playing with the setting and characters.
Design Flaw.
Spy frowned as he hummed with absentminded concentration around the gauloise clamped between his thin lips. He was cleaning his revolver, carefully maintaining the weapon he relied on in battle. His beloved butterfly knife was already stowed back in his jacket's inside pocket, razor-sharp and oiled.
Spy reloaded his pistol, enjoying the metallic noise of the shells sliding home. He frowned as he looked over the clean lines of its metal. A beautiful nude woman reclined along the barrel of the gun, embraced in a dragon's coils. It really was a beautiful likeness of the enemy Scout's mother, caught in the throes of pleasure and Spy could vouch for the veracity of the twisted lines of ecstacy transforming the woman's face. It was also outdated.
The problem with the Ambassador, he mused, was that having the likeness of your enemy's mother engraved on it rapidly became out of date as one eliminated old enemies and getting it redone every time one acquired a new enemy was time-consuming.