This is a pretty simple idea. It's a pickup, a throwable vial like the status vials, except instead of status on the target, it basically does a Nitronome explosion where it hits. Mostly for knockback, it could also deal non-trivial damage. Why not?
It could be rare like mecha knight kits, or as common as any other vial. I could go either way. And no, it doesn't have to look like a Nitronome or be called a "Nitronome vial."
The problem is, the vials have elemental power. The vials are a collection. I like the idea of having a blast vial. We can finally have a normal type vial.