Mortal Cultivation: Who Can Be More Yin Than Me, the Extreme Yin!

Demonic Cultivator + Systemless + Insidious Six + Decisive Killing. Also known as "A mortal cultivating immortality, who can be more yin than me".
The moment Song Wen killed the thin little beggar and took his blood and soul, all the cells in his body jumped with joy and his spirit was high. He knew that killing would be inevitable in this life.
In order to survive and live forever, they will sacrifice themselves at all costs.