Even the greatest product of the distinguished Sabi lineage, Sabi Kokken, a master swordsman among master swordsmen who was famed as the strongest person in the world and even the strongest in history, was not without flaws. Perfection is nothing but a word and an abstract concept. As such, while the legendary swordsmith Shikizaki Kiki strove for completion and finality beyond that, he made no attempts to achieve perfection. He knew better than anyone else that it would only led to an abyss.

Kyotou Yasuri Chapter 7