Anyone can join, with a 50-word vignette in the comments. Your vignette does not have to include the prompt term.
"Every superhero is unique -- indeed!" She raised her head and looked down her nose. "We've seen the reports on this one, and when have you ever heard of a superhero hiding his powers? He has nothing unusual. Flying Bricks, they call them. Flight, strength, speed, and senses. And some invulnerability."