This has been set up as an end of arc location to visit in Wano. Though of course Zoro isn't the narrator of this story so what he says isn't automatically fact and it's possible we get to this location before the end. Let's go through possible plot developments that could come from visiting Ryuma's temple.
A RYUMA FLASHBACK
This is possible given we are set up for a lore dump at the end of the arc specifically centered around Wano's closed borders. Gyukimaru pointed out that Ryuma was a champion of said closed borders having fought off the government apparently single handedly. Therefore there's story points that call for such a flashback however short it could be and it's possible Gyukimaru is alive to tell this story. It's also possible that there's some written or pictorial telling of this story like on the walls of the temple or something.
Given that Ryuma and Mihawk are the only two people so far in the verse to ever poses Black blades, it's not impossible to imagine Mihawk has been to this Temple before to learn about Black blades as well. This creates the possibility of their being a sign that Mihawk was there before that Zoro finds or someone straight up says Mihawk had been there before.
THE SECRET OF THE BLACK BLADES
We are expecting that there is some secret to making black blades and it's possible this is found in this Temple. Granted Tenguyama seemed to know this secret but since he didn't tell it to Zoro there and then, it's likely this will be revealed at a special time and place such as the temple.
THE DESTRUCTION OF THE TEMPLE
This predicated on the story visiting the temple before the end of the arc. The things supporting this outcome are Shusui is the best sword in the country and yet its not being used to fight for the country and the Raid on onigashima will spill out into Wano's mainland. As we saw, a clash between just big mom and kaido was threatening to destroy onigashima and given it's very likely that the assassination of kaido will fail, a full out war will break out and will definitely spill into almost every region in Wano including Ringo hence the temple of Ryuma could get destroyed.
THE LINEAGE OF THE SHIMOTSUKI CLAN
We recently learned Ryuma was called "Shimotsuki" and given the somewhat background focus of this clan and it's members in Wano, the temple of Ryuma could be where it all comes to the foreground. In case you missed them, the members so far are Ryuma, Yasu, Ushimaru, Kouzaburo, Koushirou and Kuina.
ZORO TAKES BACK SHUSUI
After his encounters with Gyukimaru, Kawamatsu and Hiyori, Zoro concedes that he might not have been as worthy of Shusui as he previously thought and trades it for Enma. This could easily change during the events of this arc with Zoro doing something that in the eyes of Wano make him worthy of possessing their Sword God's blade which he'll get back at the temple.
MYSTICISM AROUND RYUMA
This is a vague plot point but it exists. Moriah calls Ryuma's body "holy" for having survived 400 years without withering into dust(this is probaby due to the coldness of Ringo). Ryuma's corpse also admitted to feeling ancient memories from its other life coming up as it faced Zoro. The mystical fox Gyukimaru left his position guarding his bridge in Ringo to steal Shusui from all the way in the flower Capital Ebisu town having known Shusui was there SOMEHOW. Ryuma is venerated as a deity in the country with the title of a God of blades. If there is something supernatural here, then it would be brought up at the temple.
These are the common plot points speculated around the temple of Ryuma. What do you guys think? Are there any I missed?
A RYUMA FLASHBACK
This is possible given we are set up for a lore dump at the end of the arc specifically centered around Wano's closed borders. Gyukimaru pointed out that Ryuma was a champion of said closed borders having fought off the government apparently single handedly. Therefore there's story points that call for such a flashback however short it could be and it's possible Gyukimaru is alive to tell this story. It's also possible that there's some written or pictorial telling of this story like on the walls of the temple or something.
A MIHAWK CONNECTIONGiven that Ryuma and Mihawk are the only two people so far in the verse to ever poses Black blades, it's not impossible to imagine Mihawk has been to this Temple before to learn about Black blades as well. This creates the possibility of their being a sign that Mihawk was there before that Zoro finds or someone straight up says Mihawk had been there before.
THE SECRET OF THE BLACK BLADES
We are expecting that there is some secret to making black blades and it's possible this is found in this Temple. Granted Tenguyama seemed to know this secret but since he didn't tell it to Zoro there and then, it's likely this will be revealed at a special time and place such as the temple.
THE DESTRUCTION OF THE TEMPLE
This predicated on the story visiting the temple before the end of the arc. The things supporting this outcome are Shusui is the best sword in the country and yet its not being used to fight for the country and the Raid on onigashima will spill out into Wano's mainland. As we saw, a clash between just big mom and kaido was threatening to destroy onigashima and given it's very likely that the assassination of kaido will fail, a full out war will break out and will definitely spill into almost every region in Wano including Ringo hence the temple of Ryuma could get destroyed.
THE LINEAGE OF THE SHIMOTSUKI CLAN
We recently learned Ryuma was called "Shimotsuki" and given the somewhat background focus of this clan and it's members in Wano, the temple of Ryuma could be where it all comes to the foreground. In case you missed them, the members so far are Ryuma, Yasu, Ushimaru, Kouzaburo, Koushirou and Kuina.
ZORO TAKES BACK SHUSUI
After his encounters with Gyukimaru, Kawamatsu and Hiyori, Zoro concedes that he might not have been as worthy of Shusui as he previously thought and trades it for Enma. This could easily change during the events of this arc with Zoro doing something that in the eyes of Wano make him worthy of possessing their Sword God's blade which he'll get back at the temple.
MYSTICISM AROUND RYUMA
This is a vague plot point but it exists. Moriah calls Ryuma's body "holy" for having survived 400 years without withering into dust(this is probaby due to the coldness of Ringo). Ryuma's corpse also admitted to feeling ancient memories from its other life coming up as it faced Zoro. The mystical fox Gyukimaru left his position guarding his bridge in Ringo to steal Shusui from all the way in the flower Capital Ebisu town having known Shusui was there SOMEHOW. Ryuma is venerated as a deity in the country with the title of a God of blades. If there is something supernatural here, then it would be brought up at the temple.
These are the common plot points speculated around the temple of Ryuma. What do you guys think? Are there any I missed?
