Highlighting his value with another block-busting performance in the DHL Super Rugby Pacific final on Saturday, he has stepped up to the All Blacks' level, ready and willing to continue the growth in his game.
After players like the late Va'aiga Tuigamala and Jonah Lomu, and Hosea Gear and Julian Savea, Fainga'anuku shapes as another powerhouse outside back at international level.
Joining the All Blacks in Auckland this week to prepare for the three Test Steinlager Series against Ireland, he said he was a little star struck at first but was excited to be involved and get into his work.
Confidence was part of his make-up, and that came from enjoying what he does.
He understands the opportunity it gives him to grow alongside some of the best players in New Zealand.
He also took confidence understanding the selectors backed his ability to play at the next level.
While he had Crusaders teammates alongside, there were others he was eager to learn from and with the chance to make lifelong friends.
"I'm in a team full of talent and quality, and I'm excited to be a part of this journey with them and be able to head out, week in and week out, representing this nation and do the best for us.
"We've come from different franchises in the last few weeks, but the ability to be able to come as one as All Blacks should be truly special and be proud to point our shoulders and take on the world," he said.
He also understood the importance of continuing to be himself and do what he does best, no matter the environment.
"In my performances over the last few years I always pride myself on having consistency week in and week out, and every year. By doing that, it's better to continue progressing how I have while learning, and competing, against some of the best players," he said.
He felt there were always things to work on in his game, each coach had different aspects they wanted him to develop, and he expected he would find that out during training and game weeks. There might be some tough chats, but he understood it was all about getting the best from him.
Increased physicality of Test match rugby was not something that concerned him. He had a reputation for that type of play, but said it was for a good cause, and it was about taking one for the team and the community, the people and, at Test level, for the nation.
"It makes it better to be able to understand that I best throw a bit more at whatever the d-line throws at you, so there's no fear in that," he said.
Able to play in the midfield and on the wing provided the coaches with options for him, and he didn't mind being able to showcase his ability in either role.
"I try to keep it consistent and keep growing that, and make sure that if I'm needed I'm there to be able to secure 13 [centre] and also on the outside, so it's all about growth, and that I've got those tools in the toolbox ready to pull out when it's needed," he said.
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