He is the new plank in the Dunedin loose forward trio and the transplanted South Aucklander has made quite an impact since arriving in the city a month or so ago.
At 117kg and 1.93m, the 23-year-old is a hard man to bring down.
His ability to bust through tackles and attract two or three defenders every time he picked up the ball was instrumental in Dunedin's comfortable 43-24 win over Alhambra-Union at the North Ground on Saturday.
The home side had to scramble to shore up its defence around the ruck and Dunedin was able to exploit the subsequent gaps out wide.
There is a lot of value in a hard-running No8 at club level but the question is whether Vaai can be as effective at the next level.
That is why he moved south.
He had two options on the table - Counties-Manukau or Otago.
He chose the latter because Otago has a vacancy for a powerful anchor at the back of the scrum.
''There are more opportunities here. It is crowded in Auckland. There is heaps of talent there so I just needed a change,'' Vaai said.
''The main goal this year is just to play well at club level and hopefully get into the Otago ITM squad.''
Playing alongside Gareth Evans at Dunedin was a big help, Vaai said.
Evans talked to Vaai throughout the Alhambra-Union game to help him with his positioning and the pair complement each other wonderfully.
Evans' speed and work rate and Vaai's power present Dunedin's opponents with a formidable challenge.
Dunedin coach Elgan O'Donnell believes Vaai has what it takes to succeed at the next level.
''He is a very strong ball-carrier and a very good offloader as well,'' O'Donnell said.
''He is good defensively and can put in some big hits. His work-on is probably his work rate. He has to get his fitness level up.
''If he gets his fitness levels up to where they need to be, I think he will be a real force.''
Vaai knows he has to get up and get to the next ruck quicker.
He hopes to drop two or three kilograms and is doing extra fitness work before the team training sessions.
Dunedin has a crunch game against Southern at Bathgate Park tomorrow.
Vaai will pit his skills against hard-running Southern No8 Mika Mafi, and it should be a fascinating contest.
