The way I understood it, 柳生石舟斎平宗厳(Yagyū Sekishūsai Taira-no-Munetoshi) said “box seat” because it was a joke, well sort of. Whether you noticed or not, Musashi is quite famous now in the current Vagabond universe. To many, he is already “Unrivaled under the Heavens”. And of course, 伊東一刀斎(Itō Ittōsai) already is a “Sword Saint” before Takezo’s time. So, watching two of the greatest warrior ever lived to cross swords, it is a privilege. I think as a spirit, 石舟斎 was able to view them up-close, like sitting in a “Box Seat” watching a boxing match, it’s quite an enjoyment.
一刀斎will not lose in 2 hits, at least I don’t think he would, well maybe more than 2 hits. Did you notice his freaking right arm? It’s either an illusion, or he did not lose that arm. Towards the end of the chapter, as he is charging towards Musashi, you can see him drawing the blade using his right hand. It’s either Musashi is hallucinating, or 一刀斎did not lose his arm, or maybe there’s something wrong with my eyes.
Musashi will also not be disarming Ittōsai barehanded. That is the ultimate technique from the Yagyū Shinkage-ryū. But yeah I agree it would be nice to see if Musashi can reach that level someday, I think he can, because as we can see, he is struggling to choose his path. Sekishūsai’s path is very spiritual and it shows in his training and understanding of the Way. Ittōsai’s path is very self-centered, and his fighting style shows it, it’s all about stronger techniques, no spiritual learning mixed in at all.
The part where Musashi gets cut down by Ittōsai was in his head. It can be confusing because it is a real scenario. That is what would have happened if Musashi continued to be affected by Ittōsai. Musashi was falling into Ittōsai’s trap, he is being taunted by him, and losing his calmness and the ability to make a clear judgment. All part of Ittōsai’s strategy, a good strategy in my opinion, to defeat Takezo. But Takezo sort of snaps out of it by re-opening his leg wound, the pain caused him to briefly regain focus and clarity.
My prediction for 一刀斎 is sort of based on historical records and rumors, so they may not apply in Vagabond. But, historically, 一刀斎did sort of disappeared all of a sudden after小野 次郎右衛門 忠明(Ono Jiroemon Tadaaki) or more famously known as 神子上典膳(Mikogami Tenzen), the second pupil of Ittōsai, became the successor of the Ittō-ryū. Tadaaki was then appointed to serve the Tokugawa; however, it is widely rumored amongst the Japanese scholars that there is a huge conspiracy behind the school of Ittō-ryū. It is said that Ittōsai had two students, one of them is Tadaaki, his second pupil and the first would be Zenki. To determine who will be promoted to the Tokugawa, Tadaaki and Zenki had to duel to the death. Of course, if we follow the Japanese oral tradition, Tadaaki out skilled Zenki and became the successor of the Ittō-ryū school. He became one of the two official sword masters for the Tokugawa Shoguns other than Yagyū Munenori. It is rumored that after Tadaaki won, he came to the Tokugawa with Ittōsai’s sword, a symbol of approval from Ittōsai, Tadaaki explained. Ittōsai was nowhere to be found, Tadaaki claimed that he is too old and he retired into the mountains. It became a conspiracy when scholars researched into the past of Tadaaki and Zenki. According to history, Ono Jiroemon Tadaaki belonged to a wealthy Samurai family. Young Tadaaki was a promising student; he was very well educated and trained under his own family martial arts. However, according to Tadaaki, he had lots of real combat experiences through Musha Shugyō. This is where it bothers some scholars, because according to historical records, Tadaaki did not have any real combat experience other than training with wooden swords in his family dojo. And as wealthy as Tadaaki’s family, he must have had many duties to attend to on a daily basis, it doesn’t justify the claims he made about many years of Musha Shugyo. Zenki, on the other hand, did have many real combat experiences according to the scholars. He was a true vagabond, and according to how Zenki was historically described, his physique is much bigger to that of Tadaaki’s.
It was rumored that Ittōsai did not like Zenki. From Ittōsai’s view, Zenki was a somewhat of a ruthless beast when it comes to combat. Ittōsai did not like the savageness in Zenki, he preferred the educated/refined Tadaaki. Some scholars think that Ittōsai did send Tadaaki to kill Zenki, however, Zenki turned out to be the stronger one with more real combat experience and stronger body physique. So it is speculated that Zenki killed Tadaaki during the duel, for revenge, he went after the old/incapable Ittōsai to finished him off. He then took on the name of Ono Jiroemon Tadaaki, grabbed the sword from the dead Ittōsai then took off to become the Sword Master of the Tokugawa Shogun.
This is of course, all Japanese history conspiracy theories and such, so they may not be valid or true at all. But it’s interesting enough to read and understand why some modern scholars think this way. First they were curious why Ittōsai did not show up in person to promote his favorite pupil Tadaaki. Instead, he had his favorite pupil show up with his sword in hand explaining why Ittōsai isn’t here. The reasons would be he is too old and had to retire into the mountains, but as a symbol of Tadaaki becoming the successor of Ittō-ryū, he gave him his sword. Second, they wondered why Tadaaki trained with wooden sword in dojo for all his life, makes crazy claims such as having years of Musha Shugyo experiences. Third would be the name change, some did not understand why Tadaaki changed his name; he was first known as神子上 典膳 (Mikogami Tenzen), and then changed his name to小野 次郎右衛門 忠明 (Ono Jiroemon Tadaaki). Fourth would be the odd behavior Tadaaki shows in front of the Shogun. It is said that if compared swordsmanship levels between the two, Tadaaki was stronger than Munenori, but the Shogun favored Munenori better. It was said that Tadaaki later on, as the Shogun’s instructor, would often argue with Shogun’s staff. He was viewed as extremely arrogant and egotistic, at one point he defied direct orders from the Shogun himself. Now with Tadaaki’s supposedly highly educated background, why would he act this way? He doesn’t really fit his own image so to speak, but did act a lot like a ruthless, un-educated Zenki. Also, according to actual Japanese history, Itō Ittōsai never for once makes a personal statement saying that his style of fighting is called Ittō-ryū. It was Tadaaki who claimed that his style of fighting, derived from his master’s Ittō-ryū, shall now be called小野派一刀流 (Ono-ha Ittō-ryū).
Oh my, I’ve strayed off too much from main topic. Well, I think Ittōsai will lose. That is my prediction, because of what was said in Chapter 252, page 11 (
http://www.onemanga.com/Vagabond/252/11/). Musashi was imprisoned in the Nijō Castle, and during a conversation between the Shoshidai of Kyōto and Koetsu, the Shoshidai said: “Most of the 70 had been cut down by a single stroke of his sword. Even the Shogun’s instructors, Yagyuu (he’s talking about Munenori) and Ono (this is Ono Jiroemon Tadaaki) wouldn’t be capable of doing that.” So, we can all assume that the current Miyamoto Musashi is already stronger than Munenori and Tadaaki. Now thinking on this path, if Tadaaki was Ittōsai’s pupil and Ittōsai referred him to the Shogun, then at least Tadaaki should be just as good as Ittōsai. But according to the Shoshidai, not even Ono (Tadaaki) can do what Musashi did, so I think Ittōsai (who can be compared to Tadaaki) might lose.
Too long of a post, but just my 2 cents.