The Samoan scrum-half will quit the Liberty Stadium to join Northampton Saints in the summer.
But after returning from illness he is aiming to fire the Ospreys to a second successive title.
"Without question Kahn wants to finish with a bang," said Ospreys assistant coach Gruff Rees.
"We often get together to discuss things and spoke a while ago about what we wanted to achieve as a group of backs.
"Kahn was straight to the point: 'I want to win silverware. I won the league last year, I've won silverware Down Under and when I move to my next club I want to win the league there'.
"He's adamant he's a winner and he wants to win things. That's a big part of his make-up and what drives him and others in this squad on.
"Players like Dan Biggar, Alun Wyn Jones, Adam Jones and Richard Hibbard - as elite athletes they just want to win things constantly."
The Ospreys face Glasgow Warriors in a make-or-break clash at Scotstoun Stadium tonight.
A victory would drag the Scottish outfit into the play-off battle between the Ospreys and Scarlets, while a defeat will all but end their hopes.
"We know exactly what is needed from us if we want to stay in the play-off places. There are two tough games left, away to Glasgow and Leinster, and yes that's a tough run-in, but that's what we're about as Ospreys," said head coach Steve Tandy.
"If we are going to successfully defend our title then we've got to front up like proper champions, starting this Friday night in Scotland.
"We don't want to stumble over the line relying on others to slip up, if we are going into the play-offs we want to do it on merit while building some real momentum for the knock-out games.
"If you look at the PRO12 table this season you will see how the competition really is growing in stature year on year.
"There are great sides in the mix for the play-offs including last season's two European finalists and a Glasgow team that is really building something, while you've got a team like Munster who won't feature in this year's play-offs yet only a couple of weeks ago went to the Aviva Premiership champions and rolled them over in the Heineken Cup.
"To make the PRO12 play-offs will be an achievement for anyone, particularly when having to overcome the disadvantage of starting with three straight defeats which left us playing catch-up ever since.
"The boys have responded fantastically though and the form in the 17 games since means we are going into these last two matches with a very real chance of progressing.
"Have no doubt about it, this group has the attitude, spirit and desire to finish the job off. If we apply ourselves diligently and have the right attention to details then who knows what we can achieve?"