Fate/Samurai Remnant - Additional Episode 2 "Record's Fragment: Yagyu Sword Chronicles"

The magic power of the Ritual swirling around Edo attracts many oddities.
Tsujigiri of tremendous skill. A mysterious deadly blade.

Miyamoto Iori and Saber, who are investigating the situation at the behest of Sukenoshin, are confronted by a swordsman of a much higher skill. A Servant.
Is this the rumored Tsujigiri?
Just as they wonder, the Servant suddenly lowers his sword to introduce himself.

“...I am Yagyu Munenori.
A figment of human history, and now a swordsman with no master.”

A newly arrived Rogue Saber, a master of swordsmanship, whose True Name is Yagyu Tajima-no-Kami Munenori.
What is his purpose here? And what is his connection to Tsujigiri?
Accompanied by a new Servant, Iori and Saber traverse the blood-soaked streets of Edo.