As they suspected, the mist becomes very dense the further they go. Luckily, Jon's clones don't really need to breathe because they are made of pure chakra. They don't have real human organs although they can eat & breathe.
But it's not the case for the Straw Hats. They can hold their breath for a while, but they don't know if they can hold it until they come out of the mist. So they need to make preparations before they advance.
"I wonder how Roger Pirates got through this mist years ago."
"Maybe they also made air tubes to breathe."
"Or maybe this mist wasn't here when Roger Pirates attempted to reach Laugh Tale. The New World is too unpredictable. We never know when things will change here. Even this mist might suddenly disappear when we talk. Who knows?"
"Hmm? My clones have reached the solid mist area. It's not that far ahead, around 5 km. Just as we thought, the area before that solid mist is very dense, they have a hard time moving. No wind either, so we need to move the ship manually. Even then, the ship will eventually be unable to move because of the resistance."
"Then what should we do? Should we move around the mist to find any gap?"
"That is not a bad idea. Maybe Roger Pirates managed to find that gap if this mist was also here when they went to Laugh Tale. But it will take time and a lot of effort because we don't know just how wide this misty area is."
"The possibility of a gap with low density mist is not that high. Although I believe it exists or there won't be any way to get to Laugh Tale."
"If there isn't a way, we just need to make one. Jinbe, I need your help."
Jon asks Jinbe to dive underwater and swim to the solid mist area. They need to check how far they are to the end of this mist area. But they can't do it from above the water, so they need to check it from underwater.
Jinbe then jumps into the sea, but he finds a big problem immediately. It is pitch black underwater with no visibility. They all forget that sunlight can't pass through because of the thick mist, so it surely gets very dark down there.
Luckily, as a Whale Shark Fishman, Jinbe can see quite well in a dark water. Whale Sharks often swim in the deep sea with almost no light. So their eyes have adapted to see in such a dark environment although it doesn't mean he can see as well as usual when it's bright.
But there is another problem underwater beside the darkness. The water here is very thick, almost like honey or syrup, making it hard for Jinbe to swim. He is used to high underwater pressure as he lived 10 km below the surface, but he never lived in this kind of thick water.
Jinbe tries to keep swimming, but the water keeps getting thicker, similar to the mist above. 'Breathing' is also getting harder with the water being thicker & thicker. In the end, Jinbe is forced to return to the ship before he can find the end of this misty area.
"No good, huh? Then, we can only try that method now. If this doesn't work, then we can only find the gap somewhere in this massive misty area."
Jon then shares his idea. It's a simple and crude idea that sounds stupid but also makes sense. They need to destroy the mist area using their strength from here while they still can move their bodies well. If they move further to do this, they will get too much resistance to release their best attacks.
"But the solid mist wall is 5 km ahead and we don't know how thick it is. Will our attacks even reach that far?"
"It is possible if we do it correctly. We need to make a train of attacks."
"A train of attacks?"
"Well, basically, we need to send attacks consecutively in a row. So the attacks in the front will open a path for the attacks behind by destroying the thick mist which reduces the resistance. That way the last attack which is also the ultimate attack won't lose too much of its power before hitting the solid mist wall."
"Hmm, that sounds feasible. So what's the order of attacks?"
"We need long-range attacks, right? So first I want Jinbe to shoot a big and powerful water shot to open a gap until it runs out of power. Right after Jinbe shot that, we shoot Gaon Cannon which can travel further than Jinbe's water shot. Then Zoro sends the strongest cross slash attack to continue tearing the thick mist. Lastly, I will shoot the strongest Beast Bomb to completely destroy the mist in front of us. If this works, we need to move as fast as we can before the gap closes again."
"Will that really work?"
"We need to try to know."
They think about it for just a moment before agreeing to Jon's idea. None of them have better ideas, so they can only agree. The ones with great desire to do something but don't have long range attacks like Luffy feel very dejected though because they can't do anything.
Anyway, they make preparations and get ready to start the plan. Jinbe is swimming in front of yhe ship. Franky pumps Sunny's cola energy barrels and Usopp is in Gaon Cannon's control room. Zoro stands on Sunny's head with full concentration and holding all his swords.
Jon is on top of the ship's mast to make sure no one gets caught in his attack because it will be very big. He needs to make sure that his attack will be very powerful to open a path for them. It will be very big and the ship will get caught by it if he doesn't stand on top like this.
Meanwhile, the others are getting ready to move the ship anytime. They can't miss the timing to advance or the thick mist will block their way again. If that happens, then their efforts will go to waste.
"Alright, let's do this! Everyone, get ready!"
They all nod and start to charge their attacks. Jinbe starts to gather the water and forms a big water ball underwater. Franky & Usopp are loading Gaon Cannon with compressed air. Zoro is feeding his swords with haki to make his attacks very strong.
Jon is activating his Six-Path Sage Mode which is the combination of Six-Path power and Sage Mode. In this mode, he can use his overwhelming chakra as a Six-Path sage, added with Kurama's massive Chakra, and there's also Nature Chakra he gathered with Sage Mode.
Using all those different types of chakra, he creates a massive Beast Bomb with a spinning chakra blade. It's the Beast Bomb version of Rasen Shuriken that also has a massive size. Furthermore, Jon adds his left eye's Mangekyo power to cut space into this Shuriken Beast Bomb to increase its power even further.
Everyone below can feel the great power from Jon's attack, but they can't be bothered by it. This attack is their biggest hope to get through this annoying thick mist area. So they really hope this plan will work.
"JINBE!"
Jinbe shoots a very big water current to break through the thick mist. They can start seeing the mist get torn apart by that water cannon, but it's still resisting.
"USOPP!"
Usopp aims at Jinbe's water current shot and shoots Gaon Cannon. The compressed air cannon follows through the path that Jinbe's attack has opened. Then it hits the water current shot that almost stops after losing a lot of power because of the mist's resistance.
"ZORO!"
"OK! KING OF HELL: THREE THOUSAND GREAT HELL WORLDS!"
Zoro swings his swords after spinning them since a while ago. A massive cross slash attack flies forward, following Gaon Cannon's compressed air bullet. Gaon Cannon's shot reduces the thick mist's resistance a lot for Zoro's attack, so the cross slash can move easier.
"MOVE THE SHIP SO JON CAN SHOOT HIS ATTACK EVEN CLOSER TO THE SOLID MIST WALL! WE ALSO CAN'T LET THE MIST TO FILL THE GAP AGAIN!"
They move the ship forward as Nami says and Jon grins because Nami understands the situation really quickly. He wanted to shoot his attack right after Zoro sent his attack. But when seeing Zoro's attack, Jon realized that if he shoots his attack at that time, then his attack will hit Zoro's attack from behind and destroy it.
It will reduce their attacks' power and destroy their good plan. So he should let Zoro's attacks open a path until it loses its power before his attack takes over. He needs to watch very carefully and only shoots when Zoro's attack almost runs out of power.
The ship keeps advancing at the highest speed using its paddle wheels. Franky installed their paddle wheels again after entering the mist because there's no wind here. Now they are spinning the wheel manually because they've used all cola power to shoot Gaon Cannon.
After sometime, Jon can see the power of Zoro's slash attack getting weaker after hitting the solid mist wall. Gaon Cannon couldn't fully open a path until the solid mist wall, so Zoro's slash attack was cutting through the very thick mist wall and now the solid wall, which caused it to lose power before destroying the solid mist wall.
Jon throws his Beast Bomb Shuriken toward Zoro's slash attack. It flies at a very high speed and keeps its power because there's no resistance by the mist. After a while, it reached the very weakened slash attack and took over the job of destroying the solid mist wall.
The Beast Bomb Shuriken keeps spinning and cutting the solid mist wall as the crew keeps moving forward too. Zoro's slash attack managed to cut 1 km deep into the solid mist. Then Jon's attack cuts the next 3 km solid mist wall before it explodes.
The explosion is so powerful that it covers a 5 km radius. Not only that, the shockwave has an even wider range. It reaches their ship and would push them back if not for Jon blocking it by crouching in front of the ship with his susanoo.
After the shockwave is gone, they all look forward and they can see a big area of the solid mist wall has been destroyed. Then at the end of that destroyed area is a small gap with sunlight passing through. They finally find the exit of this treacherous mist area.