"Nine Swords Slaying the Heavens" was quite good indeed.
After spending nearly half a year, consuming close to ten thousand precious top-grade spiritual elixirs, and expending a massive amount of vital energy, essence, and spirit, he managed to push the Chaos Burying Heaven Coffin to evolve the technique to the level of a fifth-grade Divine Formula, but he could push it no further.
It was not that the sword technique could not be evolved any further, but rather that the consumption of vital blood was simply too great for him to sustain.
Chapter 399