So, now that we've met them, any thoughts as to why Director Lee has them on the list of potential Supervillains?
Here are mine:
Piper: possessed by an evil magical item, so that's straightforward.
Nimble: Career Criminal. Again, straightforward.
Invictus: Difficult, given how little we know of his background. That said, he's Invincible and he was apparently fighting Mr. Henry at one point, so I think I can see why Director Lee would worry about him.
Blossom: I'd be concerned if Director Lee wasn't worried about someone using Ash's magitechnology to build a self willed robo-golem.