Like this 2 weeks passed by. Everyday Kenshin would talk with the minks a bit, play with Momonosuke or more like tease him, train Wanda and Carrot and spend time understanding ways to spend his ki into electricity or have lightning nature in it.
After studying Wanda and Carrot and also asking Nekomamushi and Inuarashi to display their Electro, Kenshin learned that it is within their bloodline and their ability takes energy from their cells and convert it to electricity.
After that Kenshin studied the techniques he had stored in his soul and after a day of practice, he succeeded. Then for the next 13 days, he just improved it further and further and he has attained mastery over it as he can use most of his techniques with lightning ki imbued in it and also there is no time delay to cause a problem in the battle.
He also spent time with Wanda and Carrot teaching them proper techniques and also visiting shops and other places with them. A few days after Kenshin started teaching Wanda and Carrot, Shishilian, Concelot, and Giovanni came to learn from Kenshin.
After that Inuarashi and Nakomamushi also came to learn from him. And for the last 7 days or a week, Kenshin would just teach about martial arts to every single mink by teaching them unarmed martial art technique and sword technique by demonstrating in the stage.
These days everybody started to call him "Shifu". He kinda likes this name as it is better than the devil or others. The minks didn't have any huge breakthrough these days but they improved bit by bit.
And Kenshin not only started to use lightning ki on his weapon, but he also used lightning ki on his own body and started to use Killua's godspeed technique and Raikage's technique.
And another benefit was that by using lighting ki, his physical strength was also increasing. Kenshin's current physical prowess would be equal to Jack after he has transformed into Mammoth, so you can say it's lower than that of Big Mom and Kaido but his strength will increase.
It was magical as Kenshin always thought how a novel stands under lightning and his physique improves but similar things also happened to him. (MC is forgetting that he is not in Earth anymore and here only anime logic works)
Today was the day Jack and his minions were supposed to come and destroy Zou and harm many of the Mink tribe. So, after the morning lecture that Kenshin gave them on martial arts, he didn't practice like usual and waited for them to come.
At about 2 PM in the afternoon Kenshin heard huge sounds of destruction. He knew it was Jack and his men, so Kenshin dashed towards the front gate from where the noise was coming. When Kenshin came he saw, Nekomamushi and Inuarashi have just arrived at the time. (They have called a truce after Momonosuke came, so they came at the same time).
"Please stop the destruction, Jack. Don't destroy this city, it has 1000 years of history", said Inuarashi.
"Stop talking bullshit. Bring Raizo, the ninja from Wano here otherwise I will very much love to destroy everything", said Jack.
"Raizo? We don't know anyone of such a name. Get out of here you Rascal", said Nekomamushi.
"Hahaha, you brought this upon yourself", saying that Jack attacked Nekomamushi.
Before Nekomamushi could defend Kenshin jumped and shopped Jack. Kenshin looked at the others and said, "Finish them off before they call any more reinforcement and Nekomamushi and Inuarashi you lead them to clean all the pests"
"Yes SHIFU", all the Mink roared.
"Shifu? Hahaha, you taught them something or what", laughed Jack and started to attack.
"You will see soon enough", said Kenshin and used lightning ki and his physical strength to fight with Jack as he will be a perfect guinea pig for practicing the newly learned techniques.
After that the battle started while Kenshin was fighting Jack, Nekomamushi and Inuarashi were leading their squad to kill all of them. One of Nekomamushi squads killed a minion from Jack and saw them hold poisonous gas containers. He then alerted everybody as Jack might pull off underhanded techniques.
"Nekomamushi sama, some of Jack's men have bought poisonous gas with them", said a person to Nakomamushi.
"Go and bring more men to kill them all and capture the poisonous gas", said Nekomamushi.
"Nekomamushi sama, we seem to have grown stronger and our fighting efficiency has also increased a lot. Shifu is really powerful", said a subordinate.
"Yeah Shifu sure is great and look around to see if there are any more people coming", asked Nekomamushi.
In the place where Kenshin and jack were fighting. Kenshin easily dodged Jack and was injuring him using 3rd Raikage's techniques. And also improving his proficiency with Killua's godspeed and $th Raikage's techniques.
After a few minutes of battle, Jack undid his transformation as using his transformation to fight such a fast person is very deadly. Jack picked up his carved swords and started fighting with Kenshin. Kenshin still using without ki or swords and only using his physical strength as well as lightning ki to defend.
After the fight went on Kenshin's martial arts(palm and finger) mastery also increased a bit as he mostly uses punched after his sword. As the fight went on Jack was feeling the pressure increased bit by bit.
"Bastard you think you can use me as a stepping stone to improve yourself. Die", said Jack while swinging his most powerful sword strike. Kenshin just looked at it used Killusa's godspeed and dodged it and used 1 finger technique of 3rd Raikage to puncture the belly of Jack and the lightning ki destroyed his innards.
"You think you have won just by defeating me. Hahaha, you sure are foolish. My older brother King is also here as per Master's order to capture Raizo at all cost and Queen is at Dressrosa causing havoc", said Jack and he unknowingly gave Kenshin a piece of big news that Queen is at Dressrosa.
Kenshin thought, "It will be hard for Luffy, even with all his powers he couldn't defeat Queen as Queen is very strong but if he can awaken his devil fruit power, then it surely will be for the best".
"Oh, you said King is also here then what are you waiting for, call him. I cannot wait for him to come another time and then defeat him. I want to defeat you, minion, before going after Kaido's head", said Kenshin.
"Mad you sure are mad. Even if you defeat me and King, you are still way further from defeating Master", said Jack. After that, he used something to give a signal to King to come.
After a minute King: The wildfire came. King was fully dressed in black clothes with black wings behind his back and a weird black mast covering his face.
"Jack what the hell is this, you get defeated by a mere brat. You sure are a shame on All-Stars of Beast Pirates. Jack the soothe", said King while looking at jack who was dying with a huge puncture wound that on his belly and his internals almost destroyed.
"Big Brother, please save me", said Jack. After he had seen King, he was excited as he could live if King defeats Kenshin. But King looks at him and transforms into a Pteranodon and spit fire at Jack using his devil fruit power and said, "I will kill the shame first before torturing you brat. You know I love torture very much and now you will beg for death before me".
After that King fired his flame at Jack killing him who was barely on his last breath. Upon death, he just looked towards King with disbelief.
Kenshin was pretty bored and don't want to hear any more bullshit so he said, "Come if you want to kill but don't bullshit here". Kenshin was surprised as to why Kaido would send both King and Jack just to capture Raizo but it didn't matter as he will kill both of them here and Queen will probably be captured by Fujitora and this will weaken Kaido a lot.
"You speak too much, I will first skewer your mouth in my torture process", said King while laughing.
After that, he used his Talons to attack Kenshin, which was easily evaded by Kenshin who again coated his body with lightning to fight a new opponent.
After that Kenshin evaded every technique that King has thrown at him. He almost mastered the Godspeed technique and 4th Raikage's techniques. In between dodging Kenshin was jumping with his fast speed to reach near King and use lightning ki blade to make the cut at King's body.
After knowing that he cannot defeat Kenshin using his transformation, he changed back to his original form. After that, he took his ki to start the battle. King used his superior power, low Legendary level Busoshoku Haki, mid-Grand Master sword mastery and Haki Technique: Ryou to overpower Kenshin.
Kenshin looked at King seriously now, King was way better than expected. But still, Kenshin was happy as he will have a nice fight and not just easy win like other of the same level. In this fight, Kenshin used his physical powers and lightning ki only.
Kenshin used Lightning ki to further strengthen his body and was ready to fight. Earlier Kenshin was using a very minimal amount of ki and only coating ki on his hands and feet to use all the techniques. Now he will use a full-body clad with lightning ki to use Raikage's and Killua's techniques.
After that Kenshin and King rushed at each other to strike. The impact caused shock waves which even caused Zunisha to roar. Kenshin took a note of it and used sharper attacks to finish before Zunisha is injured.
King was using his sword techniques with Ryou which was very powerful. Kenshin was dodging some of them and if not possible using his own body coated with lightning ki to take the hit. Kenshin was sent flying away upon getting those attacks. He wasn't seriously injured but still, the pain was there.
After that they fought like this for more than 2 hours, Kenshin also used kicks and punches in between his finger and palm attacks to create more variations and improving his fighting efficiency.
King used his sword to cut horizontally buy Kenshin just jumped and dashed towards King's face and punched it causing King to fly backward.
Kenshin didn't let the chance go by and rushed towards King who was stumbling to kick King's legs. Kenshin kicked King's legs which brought King to his knees and used his knee to crush King's skull.
This attack caused King to dropdown on the ground. But still, King managed to stand but there was red color aura coming out of him. Kenshin got alerted as to what this was. King just laughed and said, "This was the trump card that I have never shown to anyone except master Kaido. This gives me Yonko level power for a full 2 minutes before me getting bedridden for a few months. This attack has caused even Master Kaido to take me seriously. My awakened power of Ancient Zoan".
After knowing the graveness of the situation, Kenshin coated his body with high GrandMaster level Haki and used his lightning ki to fight with the berserk King. Kings dashed at extreme speed towards Kenshin and tried to cut him with his sword.
Kenshin dodged that by a hair's breadth when he saw a punch coming at him which send him away by hundreds of meters. Like this, it was Kenshin's turn to get beaten. In the meantime, Kenshin has made many cuts on King's body but it seems that it will do nothing within these two minutes.
And Kenshin who has mastered Raikage's and Killua's technique just stopped using Ki and started training his Haki and if King's is right then it will be useful. Kenshin activated his mid Legendary level haki along with his physical strength and low Grand Master level Martial arts to fight.
After that Kenshin and King exchanged blows after blow. Punches, kicks, hand sword, palm techniques, and finger thrust were used by Kenshin whereas King was using his sword to cut down Kenshin at every angle possible.
The battle continues for 90 seconds but it seemed longer than that. Now Kenshin was fine except some minor injury here and there but overall he was fine. But King's power was dropping at an alarming rate. It was at this moment Kenshin used finger thrust but with Haki technique Ryou which was more advanced than King and made a hole in King's chest along with destroying the inner organs of King.
King was down on the ground dead. This battle was wonderful for Kenshin. Though he didn't improve much, he got mastery over many techniques and know that his haki will improve in a fight with Yonko.
When Kenshin defeated King, he looked around to see the Minks were watching his battle far away and the dead bodies of minions of Beast pirates were laid there. This means that Minks have finished all the pirates long before.
"Shifu" saying that all the minks rushed towards Kenshin to check if he is okay or not. Kenshin just told them he was okay and only needed rest. Then Kenshin moved to where he was living and sat cross-legged and meditated and used ki technique to heal the injury faster.
After Kenshin left, the minks cleared the rubble and threw away the dead Beast Pirates. Their 1000-year-old history was destroyed but they are happy as they were able to get revenge on 2 of the people who have helped in killing their Master's family.
Nekomamushi and Inuarashi were happy as Kaido's commanders had killed many retainers of Kozuki Oden. They knew that if Kenshin would not have been present then the survivor could be count on one hand. They just stood there and bowed towards the house in which Kenshin was. They thought Tomorrow they will give proper thanks to Kenshin after he completed his rest.