Transmuter

"You're not getting it!" Machi said, frustrated. "And I don't need to!" Killua protested as he bolted for the exit. A thread of Nen wrapped itself around him and pulled him back. "Look, Killua. Neither of us want to be here," Machi said. "Your brother's paying me to practice my Nen stitches in front of you, and you need the training, so I'm here for a week to train you."