After Whitebeard's earth shaking attack subsided. Kenshin thought, "I can't judge Whitebeard's attack but it was few times stronger than shown in the anime. So it must because of me saving Whitebeard's heart getting punctured by Squard's sword. Then it's good Whitebeard should be able to able to hold the three Admirals till the I defeat the Vice Admirals. And by using ki, I can probably defend myself against their strongest attacks. But I should first raise my Haki and Sword Mastery to peak of Master level by stimulating my potential".
Like this Kenshin formulated a plan in his head. After that Kenshin saw the five Vice Admirals were coming at him.
Few moments before-
"Onigumo how is his level", asked Strawberry.
"In the beginning it looks like we are same level with high Master level Haki and him being low Master level at sword mastery. But as the battle continued his prowess increased slowly. He is using us to improve", said Onigumo while sighing.
"Damn a mere brat is using us as his stepping stone. I don't like it but we will have to attack him together or we will be in deep trouble. We will have to kill him before he fully develops", said Doberman with a serious tone.
"Yeah, in the name of Justice we will not let this scum alive even if we have to loose some of our dignity", said Stainless.
So back to the present where the five Vice Admirals are standing in front of Kenshin. They looked at each other and a moment's later, the battle started. Kenshin was under immense pressure as the five of them have surrounded him from all sides and were attacking. If not for Kenshin's 500+ years of experience he would have faltered in this situation and could possibly have died. As in a battle one could die due to moment of carelessness.
The battle caused loud sounds and destruction. This attracted many people's gaze towards the fight. The Marines looked into the battle with surprise.
"Now, it's a surprise. He have made five Vice Admirals to gang up and fight", said Kizaru.
"Hmph wait till I kill Whitebeard, Ace and that Dragon's son. Then I will personally kill the bastard in the name of Justice", said Akainu.
"Ara ra scary. Kids these days are getting more dangerous", said Aokiji.
"Damn this brat. Where did he come from to be this powerful at this age. Contact cipher pol and find more about him", said Sengoku to his assistant while looking at Kenshin. "Bwahahaha it would be great if he could join the Navy", said Garp.
While the Marines were surprised, the Pirates were angry.
"Damn the Marines are so shameless"
"Yeah, first they tricked Squard to kill pops and now five Vice Admirals are ganging upon a kid"
"Damn the Navy. Are we pirates or they are"
"They are acting more like pirates than us"
"Vista if possible then, help Kenshin. He saved pops", said Marco.
"Okay and I see his sword mastery increasing with the fight", said Vista.
"Wait Marco, don't go now", said Whitebeard.
"Why pops", asked Marco.
"Gurararara... can't you see that brat is smiling. He is enjoying the fight. Be prepared to help him but don't do it now", said Whitebeard.
Mihawk who was looking at Kenshin's battle was shocked. He then said, "So many surprises in this war. First the kid with the most dangerous ability and now another one with such level of talent. What would be the fate of both of them and the world".
As Mihawk and Vista felt, Kenshin was slowly improving in the fight. Kenshin's body was now riddled with many wounds. After about 20 minutes of the battle Kenshin has improved from low to high Master level Sword Mastery and Haki mastery is also reaching to the peak. Now, Kenshin is beginning to exert pressure on the five Vice Admirals. Vice Admirals knew that the situation is grave and their opponent is a monster and if they didn't give their all then, they could very well die.
The fight continued for another 10 minutes. In the time when Kenshin was fighting with the Vice Admirals many things were happening. First Akainu bombarded with meteor showers killing many Pirates. Then Whitebeard attacked the wall to destroy it but nothing happened and the wall was made with very strong shock absorbing material. After that all the Whitebeard pirates and the allied pirates gathered in Moby Dick and Little Oars Jr who has some life left in him picked up the Moby Dick and threw it across the walls to the plaza.
Then the fight began even more seriously, many people died. As Whitebeard was not injured Aokiji and Akainu fought seriously with Whitebeard from the starting. Commanders of Whitebeard Pirates sometimes came to engage with the Admirals to take the burden off from Whitebeard a little bit. But they were lacking in strength to be able to engage with Admirals. So Admirals (Akainu and Aokiji) quickly defeat them and attacked Whitebeard. Whitebeard was riddled with scars. The most noteworthy of them were in his belly, one burnt and other cut wound. Aokiji and Akainu were not unscathed either. Both of them have many broken bones and internal injury but it was not seen due to them being Logia type devil fruit users.
While Aokiji and Akainu were having serious fight with Whitebeard. Kizaru was roaming around the whole Marineford and bombarding at pirates with his powers. They tried to move the execution earlier but similar to anime Crocodile killed the two executioners with his attack. Luffy also recklessly moved in the plaza. And when he couldn't continue, he begged Ivankov to give heal him even though it will cost some of his lifespan. They quickly changed the executioners and Mr.3 somehow got depressed and was on the execution stand.
Back at Kenshin, he took another five minutes to defeat all the Vice Admirals. He didn't kill them, he just defeated them and with all the injury they couldn't even move. Kenshin's goal was complete though he got a lot of scars, some of which are permanent ones like the one on shoulder, the cut on his cheeks and another in his belly. Kenshin thought, "Now with this scar I really am like Kenshin from anime". But his scar wasn't that big compared to Kenshin from Anime.
Just as Kenshin has defeated the Vice Admirals and was thinking. He felt someone use Haoshoku no Haki. Kenshin saw the marine soldiers near him also get knocked out. Kenshin knew this must be Luffy but what surprised him was that Luffy's Haoshoku was at the level of Low Master level. But Kenshin knew this will not happen everytime as this time Luffy's Haoshoku was due to very strong emotion.
Kenshin rushed towards the plaza. As everyone was paying attention to Luffy, Kenshin silently rushed towards the plaza. Akainu and Aokiji were occupied with Whitebeard and Kizaru was dealing with almost all the Whitebeard's Commanders but even with Marco acting as tank and taking damage, they couldn't injure Kizaru.
"Men, gather around and help Straw Hat Luffy. Give him support to save Ace and destroy the Navy", ordered the pirates.
"Destroy the Navy. Big words coming from the mouth of a dying person", said Akainu.
"If you are going to destroy Marineford, then I will have to kill you", said Aokiji.
The pirates then began helping Luffy by obstructing and engaging with the Marines and clearing a path for Luffy. Kenshin just reached the plaza and observed the situation for a bit. Then Kenshin saw Mihawk who was going to engage stop Luffy. Kenshin then dashed towards Mihawk to engage in a fight with him.
Luffy just said thank you and went towards the execution platform.
"Why did you help him", asked Mihawk.
"Nothing much, I am just giving him a chance to save his brother. And also to fight with the 'World's Greatest Swordsman'", said Kenshin.
To which Mihawk just nodded and started fighting with Kenshin. Kenshin observed that Mihawk was only using high Master Level haki and sword mastery but is still dominating the fight easily. Kenshin also noticed that Mihawk's physical strength is also greater than him by a large margin. But Kenshin also noticed that he is loosing on both strength as well as technique. Kenshin then remembered something from his last life, "even if both have same level of power and skill, it is possible for one easily defeat the other".
Kenshin didn't get disheartened as he saw after few minutes of fight he was showing signs of some improvement. This caused him to push forward. Mihawk who saw this was also happy as finally he got someone to fight with who can help him reach Legendary level in sword mastery.
Seeing Kenshin fight in equal terms with Mihawk, many people were shocked. Weaker ones thought Kenshin is at the same level but strong ones like Garp, Sengoku Whitebeard and the Admirals knew that Mihawk was not using full power but it is still shocking as this was enough for Mihawk to defeat average level Yonko Commanders. And seeing a young brat like Kenshin having the strength of a Yonko Commander was very shocking. If they knew that Kenshin haven't even used his ki then that would be more shocking.
But even with ki, Kenshin's power will only be little bit higher than strongest Yonko Commanders and he still need Grandmaster Level Haki and sword mastery with addition to ki to defeat Yonko like Big Mom's and Kaido.
After a few more minutes of their fight Mihawk withdrew his sword and said, "Let's fight to our hearts content later".
"Yeah, you are right", said Kenshin. Like this they both stopped their due for future. And in future duels between Mihawk and Kenshin will be known throughout the world.