Nick, like his siblings, started his martial-arts career in karate. When he turned 9, he was ready for kickboxing. By the time he was 12, he had a record of 12 wins and one loss in that sport.
Their reputation as a family of fighters made life easier at home and at school, Nick says.
"We never got physical with each other," he says. "You're so beat-up from the gym that you don't have time to fist-fight at home. And we never had problems at school because everyone knew my older sister. She hit like a dude."
That is, bullies at school could only imagine how the boys must hit.
Desiree was a state kickboxing champion at 16. Eventually, Nick's older siblings moved away from combat sports, and even he and his brother, Damien, took a break. After seven years of nonstop training in martial arts, it was time for something different.
The boys spent the next six years being teenagers, excelling at football and baseball in high school.
"We took time off to be kids," Nick says, adding that he would have pursued baseball further had he not fallen in love with Muay Thai.
"I think that, if I had continued [in martial arts] in those five years, I would've been so burned out. My body would be so broken down that I don't think I'd be able to fight. The way we trained was tough, and the way we train now is even harder."
When Nick and Damien were 19 and 18, they decided it was time to revisit martial arts. And their father was standing by.
The two began spending hours in the gym stretching, jumping rope, shadow boxing, sprinting, and sparring.
Nick, who lives in Phoenix with his girlfriend, Talie Jean Baca, trains for three hours each morning, takes a brief break to eat, and then heads to the gym for another three hours of nonstop training.
Training is Chasteen's job while Baca works for an event-planning company. Damien supports himself by working part-time as a security guard at Tempe bars.
Baca met Chasteen at the gym and since has become the publicist for him and Damien. She relentlessly reps both brothers.
"Nick and I live together, we train together, and we're moving to the top together," she says. "I'm so excited for him and Damien. Twenty-fourteen is going to be a huge year!"
The training has earned Chasteen many amateur U.S. Muay Thai Association titles: Intercontinental, Tri-State Welterweight, Western Regional Modified Rules, Arizona State Light Welterweight, Dual State Light Welterweight, and Regional Welterweight.
Damien holds amateur USMTA titles, including a Southwest regional championship.
"He's my main training and sparring partner," Nick says. "We have the same build, same heart, same techniques. It's kinda hard [when we're training] because we both know what we're throwing."
The brothers' parents always are squarely planted in the audience, cheering on whichever son's in the ring.
"My mom's the loudest one at fights," Nick says, recalling a time years ago when she jumped in the ring to confront a coach after one of his battles.
John says it's tough to see his boys getting knocked around but that it's the nature of the game.
"As I've gotten older, I have mellowed out a bit," he says. "I've been trying to keep up with them. But, at shows, I have to pin myself to my seat so I don't cause them any embarrassment."
In his first pro fight as a kickboxer, Damien knocked out his opponent in the third round.
"He's got more fights than me, even though he's my younger brother. He's put in just as much hard work, if not more," Nick says.
The little brother says he couldn't imagine doing anything else.
"For me, growing up, it was about spending time with my family. And, second, it was enjoying the fights," Damien says. "I felt the stress on me, but on the day of the fight, it just came normal to me."
Kent says Damien's name has come up as a potential pugilist as Lion Fight plans its upcoming Muay Thai matches.
"He's fought for us on a previous card. Nick and Damien always have been very professional with us. We'd certainly like to get Damien in early in 2014," he says.
Damien is scheduled to fight in China on January 11, while Nick's next fight is set for February 7 in Vegas.
Damian doesn't mind the broken bones or chipped teeth that inevitably will come.
"Nick always has been the pretty boy," he says. "I was a football lineman and weighed 220 pounds. Now that I'm lean, I don't really care about my looks. To me, scars add beauty. They mean you have a life story to tell."