Iron Giant

The Iron Giant is a legendary mechanical behemoth that wreaked havoc upon Mary Geoise two centuries ago. Its origins date back approximately 900 years to the enigmatic Void Century. Currently, it lies dormant due to an energy depletion issue and is securely housed on Egghead Island. This colossal robot stands as tall as the Ancient Giants and sports a distinctive horned helmet. Its visage and lower body are concealed by intricate grilles adorned with vertical bars. Notably, one of the horns on its helmet broke off more than two centuries ago and remains missing.

The full extent of its capabilities remains shrouded in mystery, as it ceased functioning before inflicting any significant damage. Nevertheless, it achieved the astonishing feat of scaling the Red Line, defying the scientific knowledge of its era. Furthermore, it served as a muse for Vegapunk's Vegaforce-01 project, albeit Vegapunk struggled to replicate the enigmatic Ancient Energy power source that fueled the Iron Giant. Luffy deduced that the robot was designed to operate autonomously, as no apparent cockpit for human control could be found within. During its attack on Mary Geoise, the Iron Giant was observed wielding a formidable polearm. Originally crafted nearly 900 years ago, it resurfaced unexpectedly 200 years prior, launching an assault on Mary Geoise but ultimately succumbing to energy depletion before causing substantial harm. In response, the World Government dispatched a team of scientists to obliterate it, but these scientists chose instead to conceal it secretly for further study. Ultimately, it fell into the hands of Vegapunk. The chance discovery of the Iron Giant by Luffy, Chopper, Jinbe, and Bonney on Egghead Island led to an unsuccessful attempt by Luffy to operate it manually, confirming its autonomous nature. Vegapunk later appeared and provided an account of the robot's history.

The Prophecy of the Two Kings

It is revealed what Roger and Kozuki Oden heard from the Sea Kings during their trip to Fish-Man Island. It is shown to be a discussion between two sea kings about the birth of the new Poseidon and her meeting with another sovereign who is to be born in a distant sea.

The sea kings knew that the new Poseidon would be born in 10 years and reckoned she would need 15 years to grow. So one king is Shirahoshi but who is the other one? I bet it’s Luffy. Luffy was born in a distant sea (East Blue). This means that Luffy and Shirahoshi were destined to meet. Luffy is the successor of Joy Boy and Shirahoshi is the successor of the original Poseidon. Perhaps Luffy and Shirahoshi are the reincarnations of the souls of original Joy Boy and Poseidon.

So Joy Boy and Poseidon are the names of the first 2 Kings during the Void Century to fight the 20 Kingdoms? Then the names became titles, for Poseidon it’s anyone who possesses the power to command Sea Kings while for Joy Boy it’s anyone who inherits his will. “The whales are delighted in anticipation of the day the two sovereigns shall meet again”. Well, it’s already shown in the previous arc. The whales seems so happy when Luffy finally reached the New World and this happen when Luffy and Shirahoshi already met and became friends.