Akhi, a 37-game product of North Harbour between 2011-15, played 13 games for the Blues in 2014-15, had an appearance for the Hurricanes in 2017, and 6 games for Waikato later that year before playing eight games with Connacht in 2017-18.
In between, he played in seven tournaments with the All Blacks Sevens on the world circuit, including the 2014 Commonwealth Games in Glasgow, where the side finished with silver medals.
But, it was his move to Toulouse in 2018 that saw him find a settled base, going on to become a club centurion with 159 games, while sharing in five Top 14 titles and two Champions League titles with the French powerhouse. He also fitted in eight Tests for Tonga.
Cotter said Akhi's experience on a two-year contract would be invaluable, and he expects he will compete for a starting place.
"That's his intention, to play every game.
"He doesn't have to prove anything. He can turn up, be himself and share his experience with the players. He's a quiet guy. I like the quiet guys who've been successful."
Akhi said he joined Toulouse around the time that halfback Antoine Dupont and first five-eighths Romain Ntamack were starting their careers, and it was a privilege to be part of their journey and to watch their growth.
But it was time to return to New Zealand, as his children were getting older and his wife was keen to get into the workforce.
He was keen to share his experiences with the Blues and to give what he could to the side.
He is not in full contact training yet, but is being eased back into preparation.
Having been feted by the French crowds, especially the Toulouse faithful when he left, Akhi hopes crowds will get behind Super Rugby Pacific in 2026, especially in Auckland.
Cotter said two key players who were out due to injuries in the 2025 campaign, prop Ofa Tu'ungafasi and first five-eighths/fullback Stephen Perofeta, are both back in training.
"Ofa is progressing well. We have to treat him a little bit differently. He's got a few years on him now, but he's keen after missing out last year.
"Stevie's been working and making progress and is in a good place mentally and physically."
