In Uchiha Chi's view, a truly perfected forbidden technique based on the Reaper Death Seal should work like this:
First, one must create a special vessel possessing immense capacity, control, and stability. It would act like a mysterious treasure box, waiting to be infused with boundless power.
Next comes the injection of a vast amount of chakra into the vessel. This chakra gradually breeds four Yin Release chakra aggregates within the vessel, resembling Tailed Beasts: Zhi, Mei, Wang, and Liang. Although far weaker than true Tailed Beasts, they still constitute an extremely formidable force, comparable to any Jonin.
Chapter 116