Wiliame hasn't played in the NRL since 2021, but he made his first-grade debut for Parramatta back in 2013 and also enjoyed a spell at Manly before his move to French team Catalans Dragons between 2017 and 2019.
He played 77 games for the Super League team, helping them win the million-pound game to ensure their Super League status at the end of his first season and scoring a try in their historic 20-14 win in the 2018 Challenge Cup Final.
Wiliame finished his time in the Super League with an impressive haul of 35 tries in 77 appearances.
He then moved from Dragons to Dragons, returning to Australia to sign with St George Illawarra ahead of the 2020 season.
Wiliame has also represented Fiji at Test level, playing every match of their 2017 World Cup run and suiting up for the nation nine times in total for four tries.
Despite his NRL experience, the Warriors have recruited Wiliame from French rugby, where he's currently playing for Perpignan.
“We're thrilled to secure Brayden and look forward to the experience he'll bring to the squad as well as the added versatility he offers the coaching group,” head of recruitment, pathways and development Andrew McFadden said in a club statement.