Imu is a tragic hero

During his worldwide broadcast, Dr. Vegapunk explicitly stated that the conflict of the Void Century was primarily a clash of two distinct ideologies, and he could not determine which side was morally “right” or “wrong.” If the Ancient Kingdom and Joy Boy were purely benevolent and the twenty Kingdoms were purely evil, Vegapunk, a man of science and logic who idolized the Ancient Kingdom’s technology, would likely have condemned Nerona Imu’s faction. His neutrality strongly implies the Ancient Kingdom (most likely a civilization from the Moon who came to the Blue Planet for resources) had some dark, dangerous, or extreme elements to its society.

The Ancient Kingdom is responsible for the existence of the Ancient Weapons: Pluton (a continent-destroying battleship), Poseidon (control over Sea Kings) and Uranus (terror from the skies as we saw with Lulusia’s destruction). Why would a peaceful, utopian society need to build apocalyptic weapons capable of destroying the world? Imu and the twenty Kingdoms might have formed their alliance to stop a technologically runaway civilization from wiping out humanity with the “Forbidden Sun” (power of the Mother Flame, which most likely originated from the planet's core and has been recreated in the modern era), since in Vegapunk’s words, “Joy Boy attempted to ensure that they [the Ancient Weapons] would be passed onto future generations.” In this light, destroying the Ancient Kingdom wasn’t an act of tyranny, but a preemptive strike to save the planet from mutually assured destruction.

Vegapunk discussed that Joy Boy is recorded in history as the first pirate. Throughout One Piece, piracy is inherently tied to chaos and disrupting the status quo. Joy Boy wielded the power of the Sun God Nika, a warrior of liberation who fights however he fancies, and is also considered the Warrior of Destruction in the Elbaphian interpretation of the mythos. While “liberation” sounds positive, absolute, unchecked freedom will lead to chaos. Imu may represent Order. If Joy Boy’s pursuit of absolute freedom threatened to tear the world apart (perhaps by using the Ancient Weapons to reshape the planet), Imu’s subjugation of the world might have been a desperate attempt to enforce stability and laws on a planet teetering on the edge of chaotic ruin.

The Alliance that banded together to defeat the Ancient Kingdom weren’t all power-hungry tyrants. We know the Nefertari Family of Alabasta, specifically Queen Lily, fought alongside Imu during the Void Century. The Nefertaris (Cobra, Vivi) are consistently portrayed as deeply moral, just, and compassionate rulers who love their people. If Joy Boy was the undeniable savior of the world, why would a righteous ruler like Queen Lily ally with Imu at all? Her initial participation suggests that, at the time, stopping Joy Boy was universally viewed by the other nations as perhaps the right thing to do.

Vegapunk revealed that the world sank by hundreds of meters during the Void Century due to the use of Ancient Weapons. While the modern World Government recently used the Mother Flame/Uranus to destroy Lulusia, it is highly possible that the Ancient Kingdom fired the first shots 800 years ago, causing the initial catastrophic sea-level rise. Over 800 years, the descendants of the twenty Kings (the Celestial Dragons) became incredibly corrupt, instituting the horrific system of slavery and systemic oppression seen today. However, this might be a tragic degradation of Imu’s original intent. Imu might have started as a man who brought order to a flooding, weapon-ravaged world, only to become a cold, detached immortal who allows the current atrocities to happen as a “necessary evil” to maintain the balance of power.

In this historical framework, Joy Boy was a well-intentioned but terrifying anarchist whose dream of a boundary-less world would have triggered an apocalyptic disaster. Imu was the unifier who made the hard, ruthless choices to save humanity, eventually becoming trapped in a cycle of tyranny to keep that hard-won peace intact. Perhaps his original “noble” purpose was just lost to time and power.

In the words of Dr. Vegapunk:

“Please do not assume that the ones who strike me down are evil...regardless of who they seem to be. I do not intend to discuss right and wrong here. I am not qualified to judge such things...and I do not know nearly enough about Him [Imu] in any case...”