Noah let Fergie go back to Vagona city to report the failure of his mission. He had left a large amount of dark matter inside his body to keep the Shadow Swords active, so he didn't need to control him directly.
Fergie's dead companions also had inscribed notebooks that Noah could seize, so contacting him wasn't a problem. The Shadow Swords made the cultivator Noah's servant, but the two had to remain separated to avoid unwanted attention.
Noah's plan didn't change after learning about the existence of the secret organization. His main focus would always remain on his power, and the Land of the Fallen could offer him more opportunities than any other place in the Immortal Lands.
Still, he wanted to remain informed about other opportunities. Fergie could keep him updated about them. Noah planned to precede every group sent by the secret organization if he learnt about something interesting.