legend of zelda: ocarina of time
why not reisen hans?
The word sin refers back to gutten. It's like saying, "The boy ... must begin his own journey. If you say, "Gutten uten fe må begynne reisen hans," you'd be saying, "The boy without a fairy must begin [another boy's/man's] journey.
Love that there is a Zelda reference, I am a huge Zelda fan :D