Saint Nerona Imu is the sovereign of the entire world in One Piece and one of the most intriguing characters that Oda has recently been focusing quite a lot on. While Imu was recently introduced during the Reverie arc, a lot more has been revealed about them going forward.
Thanks to Sabo's flashback of the Reverie, fans got to see a lot more of Imu and also found out quite a bit about their past. Naturally, as the main villain of One Piece, Imu is discussed quite heavily among the fans and this has given rise to some of the very best theories about this particular character out there.
5 Imu Doesn't Have A Silhouetted Appearance
Ever since their very first appearance, Imu was seen in a dark silhouette. It's very difficult to make out what they actually look like since they are always covered in pitch black from top to bottom. Fans can often see their eye, however, other than that, not much can be made out from the silhouette that Oda has given to the fans. Now, this could simply be down to the fact that Oda will do a major reveal later on in the story full, as it is entirely possible for Oda to have a specific plan in mind as to when this major reveal is going to happen, however, another popular idea is that Imu is actually in his silhouetted appearance at all time because that is linked to his power.
Imu could very well have the Devil Fruit power of nothingness or void. And, if a character were to represent void itself, then it wouldn't be a stretch to say that Imu could take on its natural form as well. This could explain why Oda has never revealed their face to the fans and why Imu always remains covered in silhouette at all times.
4 Imu Has The Chaos Devil Fruit
Another very popular idea is that Imu possesses a Devil Fruit that grants them the ability to control nothingness or, chaos at will. This would make Imu a sort of a God in the One Piece world. However, this shouldn't be surprising to any fan, given that Gods are already known to exist in this story. The Five Elders, for instance, are all Warrior Gods of the world. Meanwhile, Luffy himself is the Sun God and the Warrior of Liberation at the same time. Luffy brings smiles and joy as the Sun God to everyone.
It won't be a stretch to say that Imu would be the complete opposite and the God of Chaos and Destruction. If a Devil Fruit that can bring about this change is possible, then Imu could have another version of the Hito Hito no Mi, and his version would be the God of Chaos instead. This is an entirely plausible idea and could actually be true. Fans can only find out when Oda reveals more about the character that is Imu.
3 Imu Is Mother Nature
Another very popular idea among One Piece fans is that of Imu being mother nature's representation itself. This idea, once again, stems from the Gods of the One Piece world. Fans have recently been informed about the names of the Five Elders. In One Piece chapter 1086, the Five Elders' names were revealed to be Saint Topman Warcury, Saint Ethanbaron V. Nusjuro, Saint Marcus Mars, Saint Shepherd Ju Peter, and Saint Jaygarcia Saturn. Looking at them carefully, it is quite clear that they are based on the planets and the solar system.
Furthermore, the Ancient Weapons also form a few planets of the solar system. The ancient weapon Uranus, which fans have not seen yet, is, obviously, named after the planet Uranus. Poseidon is named after the planet Neptune, and, finally, the ancient weapon Pluton is named after the planet Pluto. Luffy, on the other hand, is the Sun God and forms the sun of the solar system. This leaves planet Earth and there is only one perfect candidate for it. This person is none other than Imu themselves. Imu could very well be the god of the earth in a way and be the representation of mother nature.
2 Imu Received The Perennial Youth Surgery
A very popular idea and even a theory among those living in the One Piece world is that Imu received the Perennial Youth Surgery. The surgery can be performed by the user of the Ope Ope no Mi, which is currently in the possession of Trafalgar Law. However, in the past, someone else possessed this Devil Fruit and they successfully made someone immortal.
That is how people know of the Perennial Youth Surgery in the first place. Ivankov, the leader of the Grand Line forces of the Revolutionary Army theorizes that Imu is immortal and had the Perennial Youth Surgery performed on them at some point in the past.
1 Imu Has Uranus
Another very intriguing theory about Imu is that they have Uranus, one of the Ancient Weapons, in their possession. Once again, this is a theory both among the fans as well as the characters in the One Piece world. Again, it was Ivankov, who theorized that if Imu is from the Void Century, then the weapon they used to destroy Lulusia could also be an Ancient Weapon. Fans already know that both Pluton and Poseidon were not used to destroy Lulusia.
That means that it was Uranus that eradicated Lulusia from the face of the Earth. While Imu does say that Vegapunk was the one who created Motherflame, the weapon that they used to destroy Lulusia, it could well be that Vegapunk only found a power source for Uranus and that is why it was used now and not in the past.