Potential and testing of his Devil Fruit

"Hoooo-Hoooo! Why is this so cold?" Nami shrunk inside a blanket as she trembled in cold. On other hand, Vivi and Mr.9 were also wearing blankets while scoffing at her.

After a few minutes, they were kicked out of the cabin where Zack and Sanji were moving out of the snow. Luffy and Usopp were playing with snow and Zoro was sleeping while being covered with snow.

It was quite a funny sight. Luffy made a disgusting snowman while Usopp made a beautiful Snow Queen but soon, the battle sparked between them as Luffy couldn't bear to see just good Usopp was at his craftsmanship.

Of course, it was just for fun but they continued slamming snow at each other. At this moment, Nami walked out and shouted.

"Everyone, I have something to say to you."

Hearing her words, six of them looked at her curiously.

She raised her fist and said " In the Grandline, I realized that my navigation skills are shit. That's why we will continue to face these extreme weathers."

"But, Nami… aren't you the skilled navigator? Do something about it?" Usopp asked.

"As I said, my navigation skill won't do much here but…"

"I will definitely adapt soon." At this moment, Nami was beaming with confidence which made four of them giggle and two of the sneer at her.

That being said, Zack was really proud of Nami. In terms of Navigation, she was probably better than any other navigator. Even Golden Lion Shiki was tempted by her navigation talent.

Just when he thought about him, Zack narrowed his eyes.

'On our way here, we didn't encounter Apis. Whether this change occurred because of our training or simply because of my existence, it's making me worried.'

'We are already in the Grandline. So, the only way to return to East Blue is by some sort of extreme means. If I remember correctly, we will face Shiki soon after Thriller Bark as long as nothing goes wrong.'

'That bastard certainly destructively uses his devil fruit but I have some better ways to use it. After I meet Robin and Franky, I must extensively research the way weapons can eat devil fruit.'

'If possible, I would like to keep Merry safe but I also know this is impossible. So, that means after Luffy defeats that guy, I will take his devil, and then I will feed it to Sunny.'

'A ship that can sail a thousand seas and thousand skies. Hahaha! That would be amazing.'

Although he was excited for Sunny, he was also feeling bad about Merry. After all, they have spent a lot of time with it and they are still going to spend more time with it.

That means his love for this ship will only grow. He walked near the mast which was now fixed after getting broken by Luffy. He was a bit sad but that was meant to happen.

He touched the metal that was used to keep the mast up and sighed.

'Merry, sometimes knowing the future is really hard. Just thinking about your fate makes me tremble. But, this journey is decided by the captain. Even though he loves you as much as another crew member except Usopp, he still needs to decide once you break down.'

'I hope you will keep living inside us. Merry, you are the first and last ship that made me cry when I saw you die. I….I am not a shipwright but I will do my best to help you sail longer.'

At this moment, his eyes were closed so he didn't notice something. It was the aura. The same aura that he awakened when Nami kissed him. It was slowly flowing into the mast. It was slowly changing the fate of the ship.

But, it was happening unconsciously. He couldn't even feel it himself. This aura was so strong.

"Huh! Luffy, did you feel something?" Sanji asked curiously as he sensed a strange aura.

"No!" Luffy looked at Sanji with confusion as he shook his head.

Tap! Tap! Tap!

Suddenly, the rain started as Nami shouted "Zack, what are you doing there? The weather is going to change again. Get ready to change the direction."

Soon after, they started fighting against the weather. It was the crazy part of the Grandline. You not only have to survive against the pirates but also have to fight against the weather.

Thankfully, their navigator was really good that she quickly adapted to the weather and managed to get them out of it. While this was all happening, Zoro was simply snoring out loud.

Not even a storm or lightning could wake him up. Zack didn't understand why. In the original timeline, Zoro was still a bit injured so it made sense that he would need to take more rest.

But here, he was completely fine. Even so, he was still sleeping like a dead man. They tried to wake him up a few times but didn't succeed.

After a long rally of weather changes, it finally stopped and they finally got some time to breathe. At this moment, everyone was lying almost half dead on the deck.

Even Zack was in no better situation. Finally, Zoro woke up. He looked at others resting on the deck and looked at the clear sky.

"Although the weather is good, there is no need to be so lazy. I hope we are going in the right direction. That's all I can say."

'You bastard' Everyone else except Zack and Luffy thought of the same thing.

'Zoro-Kun, although you are the most badass character, I still want to curse you for this.' Zack thought as he slowed his eyes. Unknowingly, he fell asleep. He realized that the training from Tekkai had caught up to him.

That training truly took a lot of toll on his body. He had to stiff his muscles every single time and it took a lot of stamina to endure the pressure from his cells.

It was so hard that Usopp couldn't even try it. He gave up instantly and said that unless he increases his physical strength by doing normal exercises, he can't train Tekkai.

Currently, only two persons were training Tekkai on this ship. Zack and Zoro!

Luffy wanted to train this but he found contracting his muscles gave him almost the same kind of training. So, he started training Contraction as Tekkai.

Sanji was training Soru but only once a day. It was simple. Soru required him to kick the ground. And, if he kicks the ship, it could make a hole and damage the ship.

As for Nami and Usopp, they were still doing the basic training. But, Nami was doing a special training guided by Zack. It was training about weather science.

Zack might be an otaku kind in his previous life. But, he was still a military engineering Student and had a fair amount of knowledge of weather science. So, using his knowledge, he formulated a plan to train Nami.

As for Usopp, he was very busy creating weapons for himself, Zack, and Nami. At the same time, he was also training a lot. The only free men were Sanji and Luffy.

But, even they were training to a certain extent. Sanji simply didn't want Zoro to get stronger than him so he was training his truly amazing martial art. Because he never trained on the ship before.

Of course, it was also because Zack asked him. After both of them joined, Zack asked them to teach him their techniques.

First of all, Zack had no mastery of a specific field. Maybe he was a bit good with throwing things around and punching his opponent. But, it wasn't like he could simply rely on his fist for everything like Garp used to do.

Second, Zack wanted to be a free fighter. That's what a pirate should be. Not restricted by any kind of weapon. He wanted to fight with his leg, fist, sword, arrow, halberd, ax, and even spear.

He didn't want to let any weapon go. But, the problem is that he can't carry all of these weapons. That's why when he consumed this devil fruit, a crazy idea came to his mind.

He wanted to know. Just how much can he truly bet?

Can he bet on the enemy's special skill, devil fruit ability, haki?

Originally, he wasn't sure if this kind of tactic would work. But, when he used his powers against his crewmates, he realized something.

Even though he won against Nami, his powers didn't increase compared to when he won against Zoro. Likewise, even though he won lost against Usopp, his powers drastically decreased unlike when he lost to Luffy.

That means the increase and decrease of his powers are completely related to the strength of his opponent.

In other words, he was getting their strength even though it was only temporary.

But, what if he gets their skills or Haki or Devil Fruit powers?

And, more importantly, what if he could make those gains permanent?

These were the hypothesis that he had developed in his mind after testing his powers. Whether he can do it or not needs to wait.

Ooo fuck!! He has completely forgotten about system.

Finding a secluded place in the ship ,he ordered system to appear. Suddenly a pop up panel showed up,

[Welcome host , due to consumption of a devil fruit after transmigration of soul into current body have fulfilled the condition for activation of guide system.

Host due to consumption of gamble gamble fruit can access to Observe menu(open), Stats menu(open), Information Query website(can be used once currently), Skill chart( low tier only ) , lucky wheel (locked, not enough luck points )and Shop( locked ). Enjoy!!!]

Seeing these ,his eyes widened wanting to test further. But suddenly came to an halt when he heard food is ready from sanji. Zack closed it making a mental note look after it soon.