Team Fortress 2
Unusual Effect: Erupting Thoughts
Reminds me of Anti-Freeze/Roboactive mixed with Burning Flames
i can see this being a reasonably high tier unusual, especially on pyro cosmetics.
maybe in the 40+ key mark for single class cosmetics and 150 + for multi class cosmetics.

i would honestly love to see this effect in-game as in my opinion it looks great :)