After the Styx Remnant Soul took control of the rules within the Lethe River, he also imprinted them into the Core Rules of the Blood Prison Space.
Any dead soul entering the Blood Prison Space that wished to transform into a higher-level Blood Ming Asura first had to drink from the Lethe River.
This would erase the memories of their previous life, sever their Karma Connection with the Ancient Greek Pantheon, and completely merge them into the Origin Power of the Blood Great Dao within the Blood Prison Space, which combined the strengths of both worlds.
At the same time, the Power of Forgetfulness within the Lethe River could also be used as a trump card. When released against an enemy, if fortune favored him, it could even directly erase a divine being's memories of controlling a certain authority, temporarily depriving them of their Divine Duty's power.
The rules of these five Styx rivers intertwined with one another, together forming the closed loop of "ferrying- oaths-punishment-purification-nourishment" within the Primordial Underworld.
After taking control of part of their rules, the Styx Remnant Soul naturally constructed an equally complete closed loop within the Blood Prison Space, one interconnected with the original.
This allowed it to establish a firm foothold in the Primordial Underworld, while also laying a solid foundation for devouring the Primordial Underworld in the future and prying loose the authorities within Chaos.
After taking control of part of the rules of the five Styx rivers, the first to benefit was the army formed by the Blood Ming Asuras. With the reinforcement of the five Styx rivers' rules, their strength underwent a qualitative leap.
The earliest Blood Ming Asuras were merely war puppets condensed by the Styx Remnant Soul through the fusion of Slayer Qi and the power of dead souls