When does Spy work best?

When is a good time to pick Spy? How can you be assured of his effectiveness? And when does Spy perform best?
Please enjoy this video that I have been meticulously working on over the last five-ish months.

My Patreon -   / hintshot  
My Discord Server -   / discord  

The intro animation is an homage to the game Later Alligator. All SFM elements were created by me, including the intro, thumbnail, and art seen throughout.

Music used:
Later Alligator - Main Theme
Osirois Music - Deltarune Chapter 2 - Queen (Orchestral Cover) -    • Deltarune Chapter 2  - Queen (Orchest...  
Later Alligator - Uncool Gator Games
Team Fortress 2 - Playing With Danger
HintShot - Trick and Stab (from the AOTBS Soundtrack) -    • Art of the Backstab - Original Soundt...  
Later Alligator - Pat's Theme
Later Alligator - Alligator New York City
Later Alligator - Cute Gator Games
Outro music by me -    • TF2 Remix - Right Behind You [HintShot]  

Thank you.