Not really a video that explains them, but here is a clip where there IHF sibeomdan demonstrates them. The techniques have, since 1997, gone through three or four changes, so please check with master Yoon (I just assume you train there ) which variation he teaches. The first variation I ever learned was very straight forward and for 99% of the time followed the rules of the way you would write them on paper. You only needed three strikes, one stab and one block. Later more strikes were added, so the techniques changes a bit. In the last (the version you see in this clip) more blocking techniques were added.
Yes, I train with Master Yoon . It's been a while since I've been to a sword class, and in those, he usually teaches other things, but I will ask him next time. This video gave me a good idea, though. Thanks!
The concept of using an asian alphabet for expressing the fundamentals of Japanese sword may have its roots in an epiphany that TOYAMA-RYU master NAKAMURA had while touring during WW II. While in stationed in Manchuria, sword master NAKAMURA Taisoburo had an inspiration while practicing Chinese calligraphy. Drawing on the calligrapher's repeated practice of the character "EI", with its eight basic strokes, Nakamura develops "EI-ji Happo" (lit: "8 Laws of the Character EI ") as a drill for practicing the basic cuts and thrusts of of his sword material. This was later formalized into "Happo-giri" (lit: "Eight Directions of Cutting") and become an integral part of his style, Nakamura-Ryu Batto-jutsu. Power Sensei was kind enough to share this information and further details about the development of TOYAMA-RYU can be found on his website.
Its important to remember that Nakamura was touring various Japanese sites to instruct in Japanese Army swordsmanship which Nakamura had helped organize into a coherent syllabus. Certainly while touring, Nakamura would have visited the KANTO Army area of Manchuria and most certainly would have spent time at the officer training school for Koreans wanting to be officers in the Japanese army. My best guess is that much of the TOYAMA-RYU-like material for two-handed sabre may well trace its heritage back to this connection. I'm sure this connection would be much better known if the Koreans were not so reluctant to admit that some percentage of their population were cheering-on the "losing side" of the war and have had to revise history a bit to cover up this potentially embarrassing bit. FWIW.