How can you call destiny a challenge?, I still play it, but I know for a fact it's bullshit and full of luck, there is no way of earning a gun, unless it's a guaranteed rewards, such as the vestian dynasty or the bounty for the thorn and bad juju. Also, when people put 'no', they are these little bitches who cry if 'their' gun is sold by Xur, maybe people don't have enough time to play the game, so Xur is a quick and easy way to get exotics, so quit bitching about you wanting Xur not to sell it, cause at the end of the day, you still have yours :)