Dion thought back to what Mandy always used in their arguments. Whenever he tried to defy her while mom wasn't home, she'd always throw out the fact she was older than him, as if that ever meant anything. With the Chronivac, however... he knew he could give her a taste of her own medicine.
He thought about how funny it could be if he turned Mandy into a toddler, too weak and young to protest against his decisions. Maybe he could even mold her into a better sister! Or maybe he could reverse the age gap, changing Mandy from 2 years older than him to 2 years younger.
The thought of making her older crossed his mind as well. "Maybe," he thought, "she'd be a bit nicer when she's older.. But do I want to take that risk?"