"Oh. That. Well, even he's not sure exactly how it works. Either he's increasing his speed and reflexes so it seems like everything else is slowed, or he's slowing down time in the area he's in. I'm not sure which one. It almost kills him to use it though, because the chakra use is massive," James said. "The only clans I can think of that have enough chakra to use it effectively without being seriously fatigued is the Uzumaki clan and the Uchiha clan, because they're known for having massive amounts of chakra."