After thinking it over, I'm pretty sure I know what Quinton's power is. Or at least I've hypothesized a power that makes sense with what we've seen of him so far.
I think Quinton can control TIME. Speed it up or slow it down. And he can use that power not only to affect the space around himself, but also to affect people.
Example: After the confrontation with Everywhere Kid and Nilus at the Plaza, he leapt from a the baloney and landed unharmed. Did he slow down the time in the space surrounding himself so that he would fall at a more moderate rate?
Also, he was able to age both himself and Niccy, making them appear older, then reverting them to their younger forms.
And finally, it would make sense if his ability to turn people to dust was just a form of accelerated aging. A rapid progression of a hundred years or more in the course of a few seconds would turn anything into dust-- including people.
I love all the cuddling in this comic. Also, I guess Abby and Bianca aren't just twins, they used to be one person? (Based on Niccy's 'now there's two of you' comment on the previous page) And with that plus knowing that Niccy didn't have powers until the kids met up with A&B's father--is their father experimenting on children? Not cool, man.
You wonderful on the dialogue. Gave enough info to be super intriguing but vague enough that I'm damned interested in finding out about their history. Especially how Jet and Quinton even became friends. I love how Jet's so protective of him.