Torturing Bertha brought multiple advantages to Noah. His body improved by leaps and bounds due to her dantian and body. Still, his greatest gains came from her knowledge.
Noah learnt a lot from her. Those pieces of information didn't involve only the layout of the Immortal Lands. He also understood how far the influence of the Crystal City spread.
According to Bertha, the higher plane was a messy place filled with organizations. Most regions in the Immortal Lands were lawless regions filled with various magical beasts and simple groups of cultivators. Yet, some of them were under the control of forces that weaker beings had to respect.
The Crystal City was one of those forces. Madame Canson was a rank 8 cultivator, and that gave her the power to build an organization around her.