Luai was an eight-year-old on a family camping holiday when Marshall led Wests Tigers to the 2005 NRL grand final title.
“Our camping neighbours happened to have a little portable TV, so we watched the game on it,'' Luai, 24, told Australia's News Corp.
“I remember my mum got me a Tigers towel afterwards, and I used it after every shower for the next five years – I just didn’t want to let go of it.
Luai - who is Sydney born with Māori and Samoan heritage - is a NRL star in his own right, having helped the Panthers make the 2020 grand final.
But he said was "a bit starstruck of Benji at first'' when he came into the Māori All Stars camp, but is rooming with him and "just trying to learn as much as I can from him''.
“He is pretty old in age, but he acts pretty young, so it was pretty easy to connect with him straight away.
“He has had such a long career, and he has been so successful. He has been my idol since day one, so I’m pretty happy to be getting this opportunity.”
Luai said Marshall – who turns 36 next week - had given him a lot of confidence to build on what he achieved with the Panthers last season.
Marshall and Luai will start together in the halves for the Māori All Stars against Australia's Indigenous team in Townsville.
Marshall will play with his brother Jeremy Marshall-King, 25, who will start at hooker, with ex-Kiwis veteran Issac Luke on the interchange bench.
Former Kiwis skipper Dallin Watene-Zelezniak and Raiders forward Joseph Tapine will co-captain the Māori All Stars.
South Sydney playmaker Cody Walker will lead the Indigenous side, which features NSW and Australia star Latrell Mitchell at fullback and Cronulla's Tonga enforcer Andrew Fifita at prop.