How does Kha'Zix interact with Nocturne?

Should be the same way as it normally works. Nocturne's ult/Graves Smokescreen don't remove ALL vision, just map vision while restricting total sight. Since Kha's passive isn't used up until procced and since it refreshes anytime he isn't visible to the enemy team this is rather unlikely. However, assuming Kha had used his passive and was nearby, if a Nocturne on his team ulted/Graves smokescreened a target AND Kha was now outside their vision range he should gain his passive.