JAKARTA (AFP) - Chinese giant Sun Yang has all the tools to be the perfect swimmer - the predatory instinct and a two-metre physique that can intimidate before a race has even started.
But the triple Olympic champion and nine-time world title holder is also one of the most divisive competitors in the pool, a magnet for controversy who seems to upset officials and rivals wherever he goes.
He has been labelled a drug cheat after serving a three-month suspension in 2014 for using a prescribed medication to treat a heart condition, saying he was unaware it had been added to the banned list.
Sun triggered a diplomatic row with Japan at the last Asian Games four years ago when he petulantly branded their national anthem "ugly".
He has also irked Chinese officials with his sponsorship deals and once spent a week in a detention centre for a driving offence.
But Sun carries on, unfazed by all the kerfuffle and seemingly revelling in his reputation as swimming's bad boy.
To those who know him best, nothing could be further from the truth. Sun's part-time coach believes the Chinese superstar is a gentle giant.
"He's actually a very sensitive guy," said Denis Cotterell. "He's very emotional and he gets upset by a lot of the things that are said and written about him because a lot of it just isn't true."
Australian Cotterell has worked with Sun for years and describes him not only as the most dedicated swimmer he's trained, but also one of the most respectful.
As China's greatest swimmer, Sun is under constant pressure to win every time he dives into the pool.
"I get cheesed off when people bring up cheap shots because they don't know what they're talking about," Cotterell said. "He's got a really nice, sensitive side and he respects people in the sport much better that the picture that is painted of him."
Sun considered quitting swimming after the Rio Olympics when he was taunted by some of his rivals over the doping ban, which he insists was nothing more than an innocent mistake.
After winning the 400m and 1,500m freestyle golds at London in 2012, he showed his incredible versatility by taking out the 200m in Brazil.
With nothing to prove and a long list of sponsors ensuring his financial security, he could have walked away from the sport.
But the 26-year-old decided to refocus his efforts on long-distance events despite finding success in sprints, meaning a lot of extra hours churning through the laps.
At the Asian Games, he has entered the 200m, 400m, 800m and 1,500m as well as the 4x200m relay - part of a process building towards the 2020 Tokyo Olympics.
"He was under so much pressure at Rio but he doesn't want to let anyone down," said Cotterell.
"He's a very proud man and he treats his position of being the number one sports star in a country that size very seriously."