Heading into the fourth quarter of a drama-drenched championship, the livestream camera zoomed in on the huddle of the USC women’s water polo team. To find the Trojans dancing. “That,” attacker Maggie Johnson said, “just encapsulates what our team is.” Third-year USC head coach Casey Moon, center, finally got that elusive national championship. @USCWaterPolo/X “Joy” has been the operative word for a team that has taken it to a new extreme. Beating California, 10–9, on Sunday at the Canyonview Aquatic Center in La Jolla gave USC its eighth national championship in the sport and first under third-year coach Casey Moon. Moon’s first two seasons had ended in heartache, the Trojans losing in the quarterfinal round of the NCAA Tournament one year and the championship the next. The coach told his players he would do everything he could to make sure they didn’t experience that feeling again. But the former longtime USC assistant coach never strayed from his belief that his team should always enjoy what it’s doing.…