Advancing bitter strength Gu, expend strength Gu and charging crash Gu to rank five was a huge project; Fang Yuan would need to use large amounts of materials and Gu worms.
Thus, often only the Gu Immortals who had blessed lands had the capital to gather a complete set of rank five Gu.
It was very hard for mortals to bear such a price.
Thus, in the mortal world, a lot of rank five Gu Masters did not even have one rank five Gu. Only people like Hei Lou Lan and Dong Fang Yu Liang who had the support of a large force behind them had one or two rank five Gu.
In the information provided by east window Gu, there was only a dark path rank five Gu that could be exchanged with battle merits.
"My enslavement path Gu originated from Chang Shan Yin, almost all are rank four and it will be extremely difficult to raise them to rank five in a short period of time. Thus, I need to concentrate on gathering Gu recipes, just in case."