In a series I won't name for sake of spoilers, there's a mini arc where the main character is tasked with entering the Realm of the Dead, more or less, of a world, and helping to correct a magical incident involving the dead there.
The "dead" themselves, would view any "living" being, who entered their realm, as a monstrous, grotesque shadow. Similarly, any "living" being would see the "dead" as the same, as monstrous, grotesque shadow creatures.
Since we've learned more about Imu's Abyss, I've believed the Abyss ties into Moria's Shadow Fruit, and Teach's Darkness Fruit. Teach wanted the Yami, to counteract Imu's Abyss Powers.
But, Moria is even more interesting: I believe the Gorosei/God's Knights use their Shadows, the same way Moria does, to avoid all physical damage. Since their Shadow, not them, is taking damage, they only take damage if Haki directly hits their Shadow, as hitting a Shadow with a branch or sword, without Haki, is the same as throwing shit at your own Shadow: without Haki that can HIT THE SHADOW, you are fucked.
This, obviously, is CoC Haki, BUT, it's not enough to "Cut" Sommers. You have to "Cut" Sommers' SHADOW to hurt him.
However, with the God's Knights and Gorosei, they have explicit tangible forms. You know.
Character Designs. Faces. Nipples. Toes.
Ahem.
Imu? That's just a black blob with eyes. So, I started thinking, okay, if Teach can theoretically Coat himself in Darkness with his Fruit, why the heck can't Imu do that with the Abyss? Does Imu have Abyss Coating? But, then, I remembered something very interesting:
Since Uta is canon, there's a chance her Fruit, and Tot Musica, the Demon Lord who used her in Film Red, who needs her Fruit to function, are actually canon, as well.
If Demon Lords are canon in One Piece... then I think we can guess Nerona Imu's backstory.
Like Orochi, Imu sought revenge, and was part of a disgraced clan. This explains Imu's hatred for the entire world; like Orochi, Imu despises other people inherently for the suffering Imu experienced, probably due to Dragon genetics. Maybe eyes, like Loki? Maybe Sapphire Scales?
Imu was ugly, unsuccessful, and associated with people everyone hated, and so Imu hated everybody, too. If this is ACTUALLY NERONA IMU, I both understand why they are in silhouette, and why they got bullied, oof. People are mean, man.
	
	
		
		
	
	
		
			
		
		 
	
Luffy NATURALLY INSULTS THIS FIGURE, it could very well be Imu's true form. Not the Demon King, JUST IMU, BABY.
Vearth is what? Earth, the world. Imu is what?
	
	
		
		
	
	
		
			
		
		 
	
"The World Itself".
Imu was one UGLY DUDE with a huge crush on Lili, and HATED JOY BOY'S GUTS for being this handsome pirate bastard.
We've all been there, right? Our ugly dragon phase? I looked and dressed worse than this in Middle School.
Hehhhhhhhhhhhhhhhhhhhhhhhhhhhh.
Eventually, like Orochi/Teach, Imu began sucking up to the Ancient Kingdom, and trying to feign an alliance between the 20 Kingdoms of the WG and Ancient Kingdom. Imu played both sides, to eventually get what they wanted: the Demon King Fruit, by sucking up to the Ancient Kingdom and stealing their stuff.
I think this Demon King is Satan, as described here in Brook's adventures of Lazy Bones Island:
	
	
		
		
	
	
		
			
		
		 
	
	
	
		
		
	
	
		
			
		
		 
	
Remember the Satanic Cultists? Who tributed Brook their Pantsu? Good times.
What if these guys DID know how to summon Satan... but couldn't because Nerona Imu ALREADY FREAKING DID?!?
The Demon King Fruit allowed Imu to gain the power they desired, and Imu backstabbed both Kingdoms at once, destroying the Alliance to pit them against each other.
Imu went to the Gorosei, the 5 Leaders of the 20 Kingdoms, and was like, "WOW, GUYS, YOU WON'T BELIEVE IT, THE ANCIENT KINGDOM IS SOOOOOOOO EVIL, LOOK AT ALL THIS EVIL, JEEZ... But... I brought you guys some special Devil Fruits... to help you fight back..."
Shocked at the true power of the Ancient Kingdom's Ancient Weapons and technology, and earnestly believing Imu's lies (most likely with a lot of fabricated evidence) go, "fuck it... we need to destroy the Ancient Kingdom. It's them or us."
Imu uses the Gorosei's Devil Fruits to entrap them, and then rebuilds the world in his image. However, the Demonk King is MUCH superior to Imu in power, and the Mythical Zoan Awakening of Imu's Demon King Fruit corrupts their mind entirely.
This is why Nerona Imu will show up to random places and be like, "SO IT WAS YOU, DAVY JONES!!!" Imu's mind is OUT THERE because their Mythical Zoan Awakening has led the Demon King to rule their mind. Imu is pretty much still living in the Void Century, thinking about the good ole days he almost married Lili.
The Gorosei realize: "Oh shit... we got conned by the fucking Devil, just like Shadow the Hedgehog", and have spent the last centuries trying to keep the Demon King satiated, so their evil would not spread. This explains panels like this: the Gorosei are babysitting Imu, to keep the Demon King possessing them from lashing out. It's a lot like the Big Mom Pirates, with Linlin: keep Imu happy, things are kinda okay. Angry Demon King? OH SHIT, SATURN'S DEAD, GUYS
	
	
		
		
	
	
		
			
		
		 
	
This also explains why Imu can't leave the Flower Room: I think the Demon King is connected somehow to the Devil Fruit Tree, the Sunlight Tree, Eve, which has been heavily speculated to exist inside of Marijoa, in Castle Pangea.
Imu hates the Sun God in the sense the Sun itself and deities associated with it DESPISE the Demon King, and are probably toxic to them. This is why Saturn could barely look at the Mother Flame, as well.
The Demon King is trying to find ways to escape from the Holy Land, but has been unable to do so.
IMO, this should be the true end-game of One Piece: when the Demon King of Marjoa escapes Castle Pangea, and is able to incarnate outside of it, and outside of "Hell" or whatever dimension they are in.
Currently, only those who sell their Soul to the Devil, like the Gorosei and God's Knights, can channel the Demon King, most likely through the "Mark of the Abyss".
The "Shadow" we see over Imu and Saturn, is literally THE DEMON KING'S SHADOW PROJECTED FROM HELL.
In the realm of the dead, the living are seen as shadows. In the realm of the living, the dead are seen as shadows.
The Demon King who exists in Hell, is projecting themselves AS A SHADOW onto Imu: it is IMPOSSIBLE to damage this Demon King, because, like Tot Musica, they exist in ANOTHER WORLD and you have to physically go there to actually defeat them.
Good chance this leads to us meeting dead characters in One Piece, as if Imu is the Demon Lord, they literally run Hell, which should be Impel Down on steroids: or, the Tar D. Eris, Tartarus, that we see on Imu's circle.
	
	
		
		
	
	
		
			
		
		 
	
Tar D. Eris/Tartarus rescue arc?
LET'S SAVE ACE THIS TIME, GUYS, GALS, AND FUTAS, WHOOOOOOOOOOOOOOO
FUTA YAMATO IN WANO ACT 4
...
ACE AND YAMATO 69 IN WANO ACT 69, YEEEEEEEEEEEEEEEEEEEEEEEEEEEEESSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
Anyway
Like with Luffy and Shanks, we'll need to gank the Demon Kig infesting Nerona Imu in both realms at once, maybe even more than 2. The Halley Mural had the Demon King fighting ERRYBODY, this is a Raid Boss threat.
	
	
		
		
	
	
		
			
		
		 
	
1st World Serpent = Red Line (Snake Soaked in Blood Dorry and Brogy mention when killing the Island Eater Goldfish at the end of Little Garden)
2nd World Dragon = Demon King Full Zoan
3rd World Monster = Demon King Hybrid Zoan
Loki, Hajrudin, Bepo, Shirahoshi, Alabasta Ship, Wano Ship, Emeth-stand in, Laboon, Lunarina, LIKE, THIS IS THE WHOLE VERSE GUYS
So, I think Nerona Imu is NOT the final boss.
What the Demon King needs is this:
1: To escape Marijoa somehow. Like I said, I think it's linked to the Sun, and the Sunlight Tree Eve.
2. A host more powerful than Nerona Imu
The Demon King we see on the left side of the Halley, in the 3rd World, is NOT IMU, IMO, it's someone stronger that the Demon King will take over.
Nerona Imu is more or less Orochi with a God Fruit.
The Demon King will end up in a Use who is:
1. Greedy and Evil enough to make this deal
2. Someone with a lot of hatred in them
3. A true top tier
It's also ENTIRELY possible, that, if the person who the Demon King takes over has a strong enough Will, they will be able to actually DOMINATE the Demon King with Haki, and use their powers as their own.
We've seen from Linlin that cannibalism allows you to absorb Devil Fruit powers, when she ate Mother Carmel.
Will Nerona Imu get eaten?
Shit, maybe.
Teach is the obvious candidate, here, but, I think Oda is writing Teach to be more of a tragic character, rather than a truly evil villain (I'd prefer this to be Doflamingo, probably)
So, EOS Final War will occur when the Demon King is freed the Marijoa, and, either at this point, or some time after, the Demon King will gain a new host.
At this point, the Demon King will either take over this stronger host to gain MUCH greater power, or, will be taken over.
Imu will be a Celestial Dragon with a tragic backstory, like Orochi, who is still completely hated because Imu's a giant fart of a person.
The Straw Hats who learn CoC will be able to fight the God's Knights, and possibly Gorosei, to damage/kill them, but, Demon King will require travelling to another world, though, his final form may occur after he's beaten in this world, and chooses a new host. In this case, the Straw Hats would have to defeat him in his own realm to release him, then destroy him again once he's released into the real world. In this scenario, it's impossible to kill the Demon King without first freeing them.
It's also possible that the Gorosei have their own realms where their Souls are kept, but, I fully expect some God's Knights to kick the bucket on God Valley, I don't think they have anything like that.
Since Gunko just turned into... like... she got waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaay more emo, but Saturn and the Gorosei literally become Youkai Demons, it would not surprise me if the Gorosei have their own Realms, ala Reality Marbles from Fate, where their "true Soul" is kept, and they'll also have to be taken down like Raid Bosses.
Demon King EOS Final Fight, YEAH, IT'S A SHONEN, FELLAS, HEEEEEEEEEEEEEEEEEEEEEEEEEEEEHAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAW
								The "dead" themselves, would view any "living" being, who entered their realm, as a monstrous, grotesque shadow. Similarly, any "living" being would see the "dead" as the same, as monstrous, grotesque shadow creatures.
Since we've learned more about Imu's Abyss, I've believed the Abyss ties into Moria's Shadow Fruit, and Teach's Darkness Fruit. Teach wanted the Yami, to counteract Imu's Abyss Powers.
But, Moria is even more interesting: I believe the Gorosei/God's Knights use their Shadows, the same way Moria does, to avoid all physical damage. Since their Shadow, not them, is taking damage, they only take damage if Haki directly hits their Shadow, as hitting a Shadow with a branch or sword, without Haki, is the same as throwing shit at your own Shadow: without Haki that can HIT THE SHADOW, you are fucked.
This, obviously, is CoC Haki, BUT, it's not enough to "Cut" Sommers. You have to "Cut" Sommers' SHADOW to hurt him.
However, with the God's Knights and Gorosei, they have explicit tangible forms. You know.
Character Designs. Faces. Nipples. Toes.
Ahem.
Imu? That's just a black blob with eyes. So, I started thinking, okay, if Teach can theoretically Coat himself in Darkness with his Fruit, why the heck can't Imu do that with the Abyss? Does Imu have Abyss Coating? But, then, I remembered something very interesting:
Since Uta is canon, there's a chance her Fruit, and Tot Musica, the Demon Lord who used her in Film Red, who needs her Fruit to function, are actually canon, as well.
If Demon Lords are canon in One Piece... then I think we can guess Nerona Imu's backstory.
Like Orochi, Imu sought revenge, and was part of a disgraced clan. This explains Imu's hatred for the entire world; like Orochi, Imu despises other people inherently for the suffering Imu experienced, probably due to Dragon genetics. Maybe eyes, like Loki? Maybe Sapphire Scales?
Imu was ugly, unsuccessful, and associated with people everyone hated, and so Imu hated everybody, too. If this is ACTUALLY NERONA IMU, I both understand why they are in silhouette, and why they got bullied, oof. People are mean, man.
 
	Luffy NATURALLY INSULTS THIS FIGURE, it could very well be Imu's true form. Not the Demon King, JUST IMU, BABY.
Vearth is what? Earth, the world. Imu is what?
 
	"The World Itself".
Imu was one UGLY DUDE with a huge crush on Lili, and HATED JOY BOY'S GUTS for being this handsome pirate bastard.
We've all been there, right? Our ugly dragon phase? I looked and dressed worse than this in Middle School.
Hehhhhhhhhhhhhhhhhhhhhhhhhhhhh.
Eventually, like Orochi/Teach, Imu began sucking up to the Ancient Kingdom, and trying to feign an alliance between the 20 Kingdoms of the WG and Ancient Kingdom. Imu played both sides, to eventually get what they wanted: the Demon King Fruit, by sucking up to the Ancient Kingdom and stealing their stuff.
I think this Demon King is Satan, as described here in Brook's adventures of Lazy Bones Island:
 
	 
	Remember the Satanic Cultists? Who tributed Brook their Pantsu? Good times.
What if these guys DID know how to summon Satan... but couldn't because Nerona Imu ALREADY FREAKING DID?!?
The Demon King Fruit allowed Imu to gain the power they desired, and Imu backstabbed both Kingdoms at once, destroying the Alliance to pit them against each other.
Imu went to the Gorosei, the 5 Leaders of the 20 Kingdoms, and was like, "WOW, GUYS, YOU WON'T BELIEVE IT, THE ANCIENT KINGDOM IS SOOOOOOOO EVIL, LOOK AT ALL THIS EVIL, JEEZ... But... I brought you guys some special Devil Fruits... to help you fight back..."
Shocked at the true power of the Ancient Kingdom's Ancient Weapons and technology, and earnestly believing Imu's lies (most likely with a lot of fabricated evidence) go, "fuck it... we need to destroy the Ancient Kingdom. It's them or us."
Imu uses the Gorosei's Devil Fruits to entrap them, and then rebuilds the world in his image. However, the Demonk King is MUCH superior to Imu in power, and the Mythical Zoan Awakening of Imu's Demon King Fruit corrupts their mind entirely.
This is why Nerona Imu will show up to random places and be like, "SO IT WAS YOU, DAVY JONES!!!" Imu's mind is OUT THERE because their Mythical Zoan Awakening has led the Demon King to rule their mind. Imu is pretty much still living in the Void Century, thinking about the good ole days he almost married Lili.
The Gorosei realize: "Oh shit... we got conned by the fucking Devil, just like Shadow the Hedgehog", and have spent the last centuries trying to keep the Demon King satiated, so their evil would not spread. This explains panels like this: the Gorosei are babysitting Imu, to keep the Demon King possessing them from lashing out. It's a lot like the Big Mom Pirates, with Linlin: keep Imu happy, things are kinda okay. Angry Demon King? OH SHIT, SATURN'S DEAD, GUYS
 
	This also explains why Imu can't leave the Flower Room: I think the Demon King is connected somehow to the Devil Fruit Tree, the Sunlight Tree, Eve, which has been heavily speculated to exist inside of Marijoa, in Castle Pangea.
Imu hates the Sun God in the sense the Sun itself and deities associated with it DESPISE the Demon King, and are probably toxic to them. This is why Saturn could barely look at the Mother Flame, as well.
The Demon King is trying to find ways to escape from the Holy Land, but has been unable to do so.
IMO, this should be the true end-game of One Piece: when the Demon King of Marjoa escapes Castle Pangea, and is able to incarnate outside of it, and outside of "Hell" or whatever dimension they are in.
Currently, only those who sell their Soul to the Devil, like the Gorosei and God's Knights, can channel the Demon King, most likely through the "Mark of the Abyss".
The "Shadow" we see over Imu and Saturn, is literally THE DEMON KING'S SHADOW PROJECTED FROM HELL.
In the realm of the dead, the living are seen as shadows. In the realm of the living, the dead are seen as shadows.
The Demon King who exists in Hell, is projecting themselves AS A SHADOW onto Imu: it is IMPOSSIBLE to damage this Demon King, because, like Tot Musica, they exist in ANOTHER WORLD and you have to physically go there to actually defeat them.
Good chance this leads to us meeting dead characters in One Piece, as if Imu is the Demon Lord, they literally run Hell, which should be Impel Down on steroids: or, the Tar D. Eris, Tartarus, that we see on Imu's circle.
Tar D. Eris/Tartarus rescue arc?
LET'S SAVE ACE THIS TIME, GUYS, GALS, AND FUTAS, WHOOOOOOOOOOOOOOO
FUTA YAMATO IN WANO ACT 4
...
ACE AND YAMATO 69 IN WANO ACT 69, YEEEEEEEEEEEEEEEEEEEEEEEEEEEEESSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
Anyway
Like with Luffy and Shanks, we'll need to gank the Demon Kig infesting Nerona Imu in both realms at once, maybe even more than 2. The Halley Mural had the Demon King fighting ERRYBODY, this is a Raid Boss threat.
 
	1st World Serpent = Red Line (Snake Soaked in Blood Dorry and Brogy mention when killing the Island Eater Goldfish at the end of Little Garden)
2nd World Dragon = Demon King Full Zoan
3rd World Monster = Demon King Hybrid Zoan
Loki, Hajrudin, Bepo, Shirahoshi, Alabasta Ship, Wano Ship, Emeth-stand in, Laboon, Lunarina, LIKE, THIS IS THE WHOLE VERSE GUYS
So, I think Nerona Imu is NOT the final boss.
What the Demon King needs is this:
1: To escape Marijoa somehow. Like I said, I think it's linked to the Sun, and the Sunlight Tree Eve.
2. A host more powerful than Nerona Imu
The Demon King we see on the left side of the Halley, in the 3rd World, is NOT IMU, IMO, it's someone stronger that the Demon King will take over.
Nerona Imu is more or less Orochi with a God Fruit.
The Demon King will end up in a Use who is:
1. Greedy and Evil enough to make this deal
2. Someone with a lot of hatred in them
3. A true top tier
It's also ENTIRELY possible, that, if the person who the Demon King takes over has a strong enough Will, they will be able to actually DOMINATE the Demon King with Haki, and use their powers as their own.
We've seen from Linlin that cannibalism allows you to absorb Devil Fruit powers, when she ate Mother Carmel.
Will Nerona Imu get eaten?
Shit, maybe.
Teach is the obvious candidate, here, but, I think Oda is writing Teach to be more of a tragic character, rather than a truly evil villain (I'd prefer this to be Doflamingo, probably)
So, EOS Final War will occur when the Demon King is freed the Marijoa, and, either at this point, or some time after, the Demon King will gain a new host.
At this point, the Demon King will either take over this stronger host to gain MUCH greater power, or, will be taken over.
Imu will be a Celestial Dragon with a tragic backstory, like Orochi, who is still completely hated because Imu's a giant fart of a person.
The Straw Hats who learn CoC will be able to fight the God's Knights, and possibly Gorosei, to damage/kill them, but, Demon King will require travelling to another world, though, his final form may occur after he's beaten in this world, and chooses a new host. In this case, the Straw Hats would have to defeat him in his own realm to release him, then destroy him again once he's released into the real world. In this scenario, it's impossible to kill the Demon King without first freeing them.
It's also possible that the Gorosei have their own realms where their Souls are kept, but, I fully expect some God's Knights to kick the bucket on God Valley, I don't think they have anything like that.
Since Gunko just turned into... like... she got waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaay more emo, but Saturn and the Gorosei literally become Youkai Demons, it would not surprise me if the Gorosei have their own Realms, ala Reality Marbles from Fate, where their "true Soul" is kept, and they'll also have to be taken down like Raid Bosses.
Demon King EOS Final Fight, YEAH, IT'S A SHONEN, FELLAS, HEEEEEEEEEEEEEEEEEEEEEEEEEEEEHAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAW
 
				 
 
		 
 
		