The Cult: Sonny Bill Williams

"Simplicity is the key and I just try to keep things as simple as I can." This is how Sonny Bill Williams once explained his successful career. Somehow, the sentiment rings a little hollow coming from a man who had at the time switched from rugby league to union and back to league again, while winning six heavyweight boxing bouts in his downtime.

And "simple" seems like an even more absurd adjective to describe a career that has since seen a second stint in union and a conversion to a third code of rugby with sevens.

Today's elite athletes are routinely described as "masters of their craft", obsessive professionals who, through years of dedicated observance to Malcolm Gladwell's 10,000 hours rule, have achieved dominion over their sport.

Against that, Sonny Bill – as he is ubiquitously known – is a throwback. He's as close as modern pro sports gets to the long-lost days of athletic supermen who would score a hat-trick for Old Etonians on Friday, bat 100 not out with Cambridge on Saturday, pick up a war medal on Sunday, before setting off for Mt.Kilimanjaro on Monday.

As an abnormally powerful 18-year-old capable of blasting men 10 years his senior off their feet with a flick of his shoulder, Sonny Bill was named the international rugby league newcomer of the year in 2004 for a debut professional season in which he became the youngest player to appear in an NRL Grand Final, and the youngest man to play for New Zealand. Even Nickelodeon rewarded him with a Kids' Choice award.

One of the most exciting players in the history of rugby league soon became one of the most exciting players in the history of rugby union, with his controversial code conversion in 2008 capped by a 2011 Rugby World Cup title on home soil with the All Blacks. The following year brought a Super Rugby title, the heavyweight championship of New Zealand, and a rejected approach from Don King. A brief return to league added another NRL premier title to his CV in 2013, with another union World Cup won two years later. By this stage, we can only assume that the mantelpiece was buckling under the weight of his silverware.

If it was the handsome face disguising a penchant for brutal big hits that made Williams a star in league, it's his impossible offloads that mark him out as one of union's most thrilling players to watch.

Going into contact, he'll have his upper and lower body battered in opposing directions by two tacklers, be toppling towards the turf at a 35-degree angle, and just when you think a ruck is imminent – pop! – the ball's gone. He's flicked it round the corner for an onrushing teammate to smash past the gainline. Sonny Bill's execution of a pass at the very last millisecond brings an attack to life in the same way that Barcelona's Andres Iniesta and Lionel Messi can tip-tap a quick-fire one-two through the penalty area and past bamboozled defences.

So, what do you do having reached the pinnacle in two codes of rugby? You take up a third.

While international stalwarts such as South Africa's Bryan Habana and Australia's Quade Cooper failed to learn the nuances of sevens in time for this year's Olympics, Sonny Bill thrived in yet another new code, although an injury just minutes into the competition cut short his playing time in Rio.

That's the staggering list of achievements behind the "SBW" legend. An athletic freak who travels the world taking up different sports involving huge men with huge muscles and then lording it over them. Throw in Channing Tatum good looks, an unassuming personality and a socially conscious mind – he has campaigned for New Zealand to take in more refugees from the Middle East – alongside reaching world-class level in three sports and national level in another, and Sonny Bill should be rugby's golden boy.

But he's not. Instead, he's rugby's gifted outsider.

If you aren't a rugby fan and have never seen Sonny Bill play, you might have formed a picture in your head of what he looks like: bearded, unkempt hair, bootcut jeans, boden shirt, wax barbour jacket, worker boots. The kind of guy who might tumble out of a Clapham bar at 3am bellowing abuse at an Uber driver down the phone. The kind of guy that puts you off ever going to watch a game at Twickenham for fear of having beer poured down your back for "banter". The rugby lad.

Sonny Bill Williams is none of those things. He hasn't been since 2008.

There was a time when Sonny Bill Williams was someone who contributed to rugby's booze-soaked image. Urinating in public? Check. Drink driving? Check. Tryst in a toilet? Check.

Those indiscretions, invoking humour as much as moral outrage, made him the Australian tabloid equivalent of Mario Balotelli circa 2011. But it was his mid-season, mid-contract walk out from the Bulldogs to go and play union for Toulon in France that, for many, has come to define him more than anything else.

Rugby players can hurl dwarves through pubs or abuse their livers and we'll roll our eyes, maybe tut-tut. Sadly, it's ultimately what's expected. But breaking the dressing room code – hard earned through hours of compromising initiations – and placing personal ambition above your band of brothers? That's just not rugby. That's football.

"For the first time, a player dictated entirely to not just one sporting code, but two," wrote Australian journalist Paul Kent of Williams' conversion in his book, Sonny Ball. "He forced them to a place where, when all is said and done, star power eclipses everything."

This has usually been framed – including by Kent – as an unequivocally bad thing. Something foreign to rugby. Sonny Bill hasn't been able to shake accusations of fierce individualism ever since. There were reports of sulking and agitation when he was not picked for the All Blacks ahead of the 2011 World Cup, while his late reversal on a decision not to play in the 2013 Rugby League World Cup cost a young player his place in the squad. It was greeted by some in New Zealand as another example of Sonny Bill doing what Sonny Bill wanted, with little regard for anyone else.

But that's not the only point of difference first marked by a 2008 conversion. Shortly after joining Toulon, Sonny Bill converted to Islam, becoming the sport's only high-profile Muslim.

He's not had to fight against institutionalised prejudice for his religion, nor could he be accurately described as a rugby pilgrim who has brought the sport to a new audience. But Sonny Bill's faith – and the seriousness with which he treats it – indisputably set him apart in a sport steeped in stuffy anglo-antipodean booze culture.

For anyone who loves rugby but feels uncomfortable with that culture – and we do exist – Sonny Bill represents a refreshing tonic, an inverse John Daly for rugby. As unfair as the tropes dumped on the sport by outsiders sometimes are, Sonny Bill still subverts all of them. He doesn't dress like a typical rugby player (think Huaraches and snapbacks rather than barbour wax jackets and button downs), doesn't act like one, and certainly doesn't play like one.

His lucrative career-hopping has been met with skepticism from people embedded within the sport. But, for those on the outside looking in, Sonny Bill is a standard bearer.

Just as he had done four years earlier, Sonny Bill started on the bench in the 2015 World Cup final at Twickenham. Yet in contrast to the 2011 game – which followed murmurs of dissatisfaction at being denied a starring role – 2015-spec Sonny Bill appeared at peace with his status as third wheel to Ma'a Nonu and Conrad Smith in midfield. He was used by head coach Steve Hansen almost exclusively as a second-half power play against tired defences, and to no greater effect than in the final, when he immediately produced two tight offloads with his two first touches to set Nonu free to score.

Yet more than the crucial assist, Sonny Bill will be remembered for his post-match act of charity in giving his medal to a (let's be honest, somewhat entitled) kid who ran on to the pitch to celebrate with the team. A viral news website's dream, another point of difference for rugby's weird wonder.

"The most gifted footballer I've ever seen,"––Eddie Jones.

@joehallwords