This time last year, the then Crusaders assistant coach Leon MacDonald gave Mo'unga a huge compliment when he compared his temperament, if not quite yet his ability, to the great Dan Carter.
After a late start due to injury last season, Mo'unga was a big reason why the Crusaders won their first title in nine years, Robertson's first as head coach.
After coming back stronger from a broken jaw this campaign, he is looming as a key cog in the machine as they seek to defend the title.
Mo'unga's kicking game was probably the main difference on a miserable night at AMI Stadium. He kicked further, more often, and more intelligently than his opposite Barrett, the 2017 World Player of the Year. The Hurricanes, who thrive on front-foot ball, or at least dry ball anyway, couldn't cope with the home side's defensive pressure.
The third quarter was probably the key. The Crusaders finished the first half by attacking the Hurricanes line but couldn't add to their narrow 7-6 advantage and shut the door on the visitors after the break by playing virtually the entire game in their half.
Reed Princep's late try, which denied the Crusaders a bonus point, was the only shot fired by the Hurricanes after the break.
"I thought we really nailed halftime," assistant coach Brad Mooar said.
"The messages to the boys were really clear. We wanted to get ahead and make them chase the game. It was a really hard night to play any footy and chasing the game makes it even harder, so it was really important to get the momentum early in the second half."
They did that and now the Crusaders will want to take that momentum into their next game against the Chiefs in Hamilton next Saturday before their bye.
Home matches against the Highlanders and Blues remain after that. Robertson's men remain masters of their own destiny and in Mo'unga, they have just about the best ringmaster of all.