At the Marine HQ, Fleet Admiral Sengoku waited for everyone to find their seats. Chojusen was among the last to arrive as he had to get his small fleet of ships before returning to the HQ. He noticed that this was going to be quite the interesting war, as only Vice Admirals and above were allowed in the meeting room, while Captains and below could only see the meeting progress with Transponder Snails.
The Fleet Admiral started the meeting "Men! As you no doubt know by now, we have captured the infamous right-hand man to Whitebeard, Flame Fist Ace! The man is a world renowned pirate, strong enough to have a bounty of 550,000,000 berries on his head. In the next coming month, we will be executing him publically right here on our very island of Marineford!"
As the Fleet Admirals voice died down, the first to respond was actually Vice Admiral Garp, who said "Fleet Admiral, why must we execute him? Wouldn't locking him up in a cell of Seastone, be enough? We would just be inviting another pointless war by doing this, and with Whitebeard no less."
One of the Admirals spoke up in pure destestment of Garp, The man of Magma, Akainu said "Shut your worthless trap! This pirate had it coming his way when he decided to join the Whitebeard Pirates! And don't pretend for a second that you don't know of the REAL reason for why we're doing this!"
As Garp heard the retort of the Admiral, he became silent and let the meeting continue without a hitch. The Fleet Admiral then began to give out details of the mission, and Chojusen, only interested in the upcoming fight didn't pry for more information.
The month came and when, but not without some upheavals caused by none other than Luffy and his crazed antics. Going to the most heavily guarded prison and fighting to breakout his brother… the prisoner to be executed!!! Too bad his brother had been moved before he could break him out, and now waited to be executed in a couple hours.
In the time before Ace's execution, the seven Warlords of the Sea came to Marineford to prepare for the inevitable war between the World Government and the Whitebeard pirates. As time passed, Chojusen started calling into question his position and what side he should fight for. He had only beem on the marines side since he had found pirates to be worthless trash in needed of being cleaned up, but Luffy subverted that view by being a nice person despite his lifestyle of piracy.
While having this internal dilemma, Chojusen decided to pay Garp a visit and ask him what this "real reason" for executing Ace was, as he remembered that there were some suspicious undertones to the conversation between him and Akainu during the meeting. However, before the two could hold a conversation, a fleet of pirate ships appeared on the horizon, signalling the start of the war.
Garp couldn't spare time talking to Chojusen after the war began, so Chojusen was left to reflect on the situation for a while longer. He was a rather special existence within the Marine Corps and would not be forced to fight in this battle; he had only come with that intention, but now that was put under question.
Chojusen watched the fight progress from the sidelines and sat down next to the three Admirals tasked with "guarding" Ace. No one dared to question Chojusen's authority to do this as his Dao of Will had reached a certain point where willpower would discreetly flow out of his body give off a special warning; a warning that said "Don't bother me unless you wish for death." Of course, this special warning would only trigger when Chojusen wasn't in the mood to deal with pointless meanderings.
Eventually, the man, myth, and legend, Yonko Whitebeard appeared and gave everyone a taste of his power. From several kilometers away and in this world void of energy, Whitebeard used his Devil Fruit power to quake the air and create all sorts of natural disasters. Tsunamis, and Earthquakes moved the terrain in Marineford like it was a joke.
Chojusen was naturally not affected by this as he had many ways to ignore such attacks, but he did acknowledge that getting hit head on by these "quakes" would be disastrous even for him. He just kept thinking and biding his time… Eventually, the pirates passed through a grand fleet of over 50 warships of the Marines and touched land on the Marineford Island.
The war raged on, and from the sky, at the most arbitrary of moments, Luffy and a new gang of misfits arrived. Both sides fought valiantly and Luffy even managed to get extremely close to Ace, but then the Fleet Admiral made an announcement to shock the world. He revealed Ace's identity of being the son of Gol D. Roger, the previous King of pirates, and also revealed Luffy to be the son of the leader of the Revolutionaries, Monkey D. Dragon.
"Mhmm? Another one of these revenge kills?" Chojusen almost couldn't believe it. This plot to kill Ace was because of his heritage? Really? This along with all the other horrendous things he had seen from the Marines made him finally reject them and leave once and for all.
…
On the elevated platform where Chojusen, Ace, and the Three Admirals stood, Chojusen slowly got on his feet and started approaching Ace. His "sudden" movements warranted Akainu to get in his way and bark "And where do YOU think you're going?"
"To save my friend's brother; duh~" Even though this was said with a playful tone, Chojusen didn't even try to conceal his indifference to the Marines.
Now all three Admirals moved to block his way and the Fleet Admiral, who stood in an even more elevated platform, asked Chojusen "Are you deserting?"
"And what if I am?" Chojusen remarked, arms shrugged and posture lax.
The Fleet Admiral sighed and said "I doesn't have to be this way..."
"Oh, but it does. I've been in the Marines for long enough to know that it's not all lollipops and sunshine. And the corruption and miss-deeds of these so called enforcers of the law have started to get on my nerves."
Once again the Fleet Admiral sighed and commanded the Admirals to stop Chojusen from rescuing Ace. Yet, it only took a single concentrated burst of Conqueror's Haki to freeze the Admirals into submission; Chojusen had locked them down with pure willpower. Chojusen nonchalantly walked through the Admirals and directly shattered the Seastone handcuffs restraining Ace from using his Devil Fruit power.
As this took place, literally everyone stopped to watch this new situation unfold. The Fleet Admiral now deemed Chojusen to be a threat at or above Whitebeard's level and directly moved to stop him. He turned in to giant golden Buddha and sent an aura blazed punch Chojusen's way. Now if it weren't Chojusen that faced this punch, rather the ground, the perhaps a kilometer deep hole would form. Fortunately it was Chojusen who faced this strike and to combat it. He only used Armament Haki, which at this point had also grown to the point where a black aura of will manifest around the are coated, and directly countered the strike with his hand.
Just imagine for a second a small normal human sized hand blocking a titanic Golden Buddha's giant palm; Chojusen's entire body was just a speck, but he managed to spot the Buddha, like a mantis holding off a chariot.
Chojusen dragonified his arms and said "Beam!" before a horrifying grandmist beam of unbearable weight sent the Fleet Admiral flying through the air. Chojusen had been developing his Devil Fruit powers as well as his Haki throughout his adventures, so some of his energy attacks could be performed while under his transformed state.
The rest of the war, if you could call it that, consisted of people attempting to stop Chojusen only to either fail miserably or get blow away to another island or even sent into the sea. The three Admirals and six of the Warlords on the World Government's side all tried to bar Chojusen's path but any of his abilities used to even 50% of their full power could take care of them with no problem. To Chojusen's surprise Boa Hancock had also been apart of this war, but even as a Warlord she had been on Luffy's side; how odd.
Chojusen led Ace to Luffy and then the three of them went over to Whitebeard's side to thank him for his assistance. As they were having a conversation to see where they go from there, an annoyance in the form a Pirate Blackbeard emerged and tried to sow chaos in this scene.
Eventually coming to know that this Blackbeard was a traitorous pirate that killed his own crew mate for a Devil Fruit and sold off Ace to be executed, Chojusen reserved no restrained when dealing with this cretin, directly destroying him with an Armament Haki infused staff blow to his chest; the pieces that remained of this Blackbeard, could be seen shuttling through the sky and maybe even into space.