In One Piece Chapter 1055, Momonosuke makes an interesting point when defending Monkey D. Luffy from Admiral Ryokugyu, if they (the people of Wano) can’t defend themselves after the Strawhat’s leave then they’re doomed. Wano had been under the oppressive thumb of Kiado for decades. As Ryokugyu notes Kiado acted as a “deterrent” preventing the Marines from invading Wano. During this conflict, we see the variety of abilities Ryokugyu’s Mori Mori no Mi devil fruit ability.
Raizo attacks him with Ninpo: Maki Maki no Jutsu: Fire Release at first it seems like the fire is a natural enemy of Ryokugyu’s plant body, it turns out that he’s immune to fire. On top of that he can continuously regrow his branches making the Red Scabbards cutting them off pointless. The fight is interrupted when Red Haired Shanks uses his Haoshoku Haki to stop Admiral Ryokugyu in his tracks. Shanks chastises him for stopping the “new shoots” from changing history. Ryokugyu appears to stand down.
The secrets of Wano
Kozuki Sukiyaki, Nico Robin, and Trafalgar D. Water Law explore “old” Wano from 800 years. Old Wano was submerged after the two walls were erected forcing the citizens of Wano to flee. The Poneglyph is located in old Wano. It’s the third Poneglyph out of four needed to reach Laugh Tale. Sukiyaki says that Pluton, one of the three Ancient Weapons, is located on a lower level. However, in order to get to the weapon the two walls must come down. Despite this Oden still wanted to open the borders which would release the Ancient Weapon. It’s still unclear why he was willing to expose Wano to the dangers of outside world. My best guess is he thought the risk was worth it to have the people experience the rest of the world.
Poneglyphs are an aspect of One Piece universe that I haven’t paid much attention to. Poneglyphs “are massive, cubic steles made of a currently unidentified, indestructible type of stone”. There are three types: Historical Poneglyphs, Instructional Poneglyphs, and Road Poneglyphs. Historical reveals “pieces of ancient history,” Instructional Poneglyphs focus on “instructions and/or clues about the locations of Historical Poneglyphs,” and Road Poneglyphs tells a reader a “detail a location.” The Road Poneglyphs can lead the readers to the location of Laugh Tale. There are only 30 in the world and are considered dangerous by the World Government. I hope the series elaborates on Poneglyphs and their history.