"Nae danger" is a scottish expression for "no chance". Power ranger is used to almost mock the person, challenging them when they think their right and clearly not. When combined, the desired effect of the phrase is to say "no chance 'big' man".
In an arguement:
Boy: "Captain Jack Sparrow's the coolest character man."
Girl: "STFU, CLEARLY WILL"
Boy: "Pfft.. nae danger, power ranger.."