As we all know, Whitebeard is the ability of the Earthquake Fruit, which is known as the strongest superhuman fruit in the world, which can cause vibrations at will, and even cause tsunamis, causing natural disasters such as earthquakes, and can be said to have devastating power.

At his peak, Whitebeard is said to have terrifying strength that can rival three admirals by himself.

However, sometimes the power of the Devil Fruit does not necessarily bring all the benefits to the owner, just like Luffy's rubber fruit, when entering the second and third gears, it uses the characteristics of rubber to produce the same principle as a pump to accelerate its own blood flow to obtain faster speed and stronger strength, but the consequence of this is a huge load on the heart, and the more you use it, the greater the damage to the body.

Shake Fruit also has this problem, Whitebeard because of eating the Shock Fruit, and became a shock person, when he uses his ability, his own body will also vibrate, which has an impact on his own bones, muscles, blood and even internal organs, and this effect may not be very visible when Whitebeard is young, but as he gradually ages, this effect begins to appear.

In short, the deterioration of Whitebeard's physical condition is not just due to old age, but the result of many reasons.

"We gave Ain an ability to Daddy!" Marco said: "Daddy's appearance does look 12 years younger, but the problem is that his physical condition can't go back, and the most troublesome thing is that the ability to regress the fruit is only temporary, once Aine falls into a coma or falls into the sea, her ability will be invalid, and Daddy will change back then." ”

Hearing this, Ian nodded thoughtfully, if he really expected the Regression Fruit to keep Whitebeard in his youthful appearance, then the people of the Whitebeard Pirates would have to protect Ain in turn, not let her fall into the sea, and not let her fall into a coma, no matter how you look at it, it feels so troublesome......

Ian has seen and knows a lot of Devil Fruit abilities, and he found an interesting phenomenon, it seems that some superhuman fruit abilities will expire after encountering sea water!

The simplest example may be Moonlight Moria, the zombie army he created with his shadow ability, once it comes into contact with salt and sea water, those shadows will fly back to the original owner, Aine is also superhuman, I don't know if her ability also has this drawback, if there is, it won't be interesting.

Sure enough, what keeps you young and the like is actually a lie...... Although the Regression Fruit sounds very buggy, but after careful study, it is not that powerful, and the ability of this fruit is still quite useful in terms of combat, but it is useless to expect to use this ability to restore Whitebeard or Zefa to peak combat power.

Ian wants to return Whitebeard's favor, but now that he looks at it, the path of Ain's Regression Fruit won't work, so he can only use the ability of Inoue's card, but the problem is that Ian doesn't know how useful it is for Whitebeard.

Generally speaking, Ian uses Inoue Orihime cards to treat injuries, but Whitebeard's injury or something, it's a small problem, it's just some old injuries, his main problem is the aging of age, in Ian's mind, even if it's Vientiane's refusal, I'm afraid it can't even be a person's age to refuse back, right?

The specific effect can only be understood when we really test it......

After the four of them played a few more rounds of mahjong, they stopped, and after putting away the mahjong, Ian and Ace walked to an open position with their fists clenched, while Fuji Tiger and Marco watched from afar.

These days, although he has been on vacation to play, but Ian's exercise has not relaxed at all, every morning after getting up, he is under the gravity of the vine tiger, to complete his workout, and in his spare time, will sit down to play mahjong with the vine tiger to gamble money.

In addition, Ian now has one more task, which is to train Ace!

Don't get me wrong, in terms of physical skills, Ian and Ace are only half a catty, and he can't teach Ace, the only thing Ian can guide Ace is that he is the ability to burn fruits.

Ian had always felt that Ace's ability development seemed to be going in the wrong direction.

Compared to when he first got the burning fruit, Ace has now developed a lot of moves that use flames, and his flames are becoming larger and more powerful, and a fire punch can even directly destroy a ship.

However, this is only a superficial application, and Ian feels that Ace has not grasped the essence of the burnt fruit.

What is the essence of burnt fruit? Temperature!

Ian himself is also playing with fire, he has played the Flying Shadow's Evil King Yan Sword Killing Flame, he has also played the flame of the Black Dragon Wave, and even played the Cangyan of Yagami, so it can be said that he still has his own intuitive feelings about flames.

In Ian's opinion, the development of flame ability doesn't care about what shape it is, it doesn't care what size it is or not, the key is still the temperature, and Ace has always made a mistake.

So these days, Ian has been trying to correct Ace's philosophy.

"Come on, let me see how much your temperature has increased now!" Ian snapped his finger at Ace.

Ace nodded, but did not speak, his body instantly turned into a raging flame, and the whole person immediately turned into a fire man, as if the volume of his body had also become larger.

However, Ian frowned and looked at the changes in Ace, and he found that Ace's current flame temperature had indeed increased, but this increase was brought about by increasing the burning area.

If you look at conventional physics, this makes sense, which means that Ace actually burns more violently by being exposed to more oxygen.

If you want to really increase the temperature of the flame, the best way is to start from the fuel aspect, use different fuels, and the temperature brought by combustion is also different, but the problem is that Ace is now a flame himself, and he doesn't have any fuel of his own, and when he keeps the elementalization, in fact, the consumption is only his own physical strength, and from this point it can be seen that the Devil Fruit is unscientific.

Fortunately, from the very beginning, Ian did not expect to solve such an unscientific thing as Devil Fruit through scientific methods, and he knew very well that even without the help of external forces, there was a way to control the temperature.

Because Ian has seen such a person, Pheasant Kuzan!

The pheasant's freezing ability, in the final analysis, is to lower the temperature, he was originally a Devil Fruit ability, but he can freeze the seawater, instead of being incapacitated by the sea water in reverse, and this is the reason.

Ace's ability is actually quite similar to that of a pheasant, ice and fire are a pair of antonyms, lowering the temperature makes the object freeze, and increasing the temperature makes the object burn.

And Ace now has to learn from the pheasant, from controlling the flame to controlling the temperature.

In Ian's chattering words, Ace has been trying to do what he says, but it's really difficult, imagination is one thing, specific operations are another, Ace this guy stood in place for a long time and maintained the shape of a Super Saiyan, the raging flames rose into the sky, but the actual effect was little.

Since Ian himself is not a Devil Fruit ability, he can't specifically understand Ace's feelings after being elementalized, so he can only guide Ace through words, and after a while, Ace stopped a little out of breath and said, "No, Ian, let me see your black flame again!" ”

Ian nodded, untied the spell bandage on his right hand, and now every time he was free, he would keep a black dragon wave on his right hand, so naturally he could let Ace observe at any time.

After untying the spell bandage, the huge heat of the black dragon wave suddenly emitted, the high temperature of the black dragon wave, ordinary people could not get close to watch, but Ace was an exception, he was even able to touch the flame of Ian black dragon wave with his own hands.

Not only him, but the immortal bird Marco is also one, although it is an animal-based phantom beast species, but Marco is also a man with his own flame, of course, the kind of flame he transforms does not seem to be a real flame, but this does not prevent him from being able to contact Ian's black dragon wave.

"Hehe, every time I see this black fire dragon, I feel amazed! Although when I transformed, the flame was also blue......" Marco crossed his arms and said to Fuji Tiger next to him: "But, is there really such a black flame in this world?" No matter how hard Ace tries, I'm afraid he won't be able to turn his flame into this black, right? ”

"Perhaps!" Fuji Tiger stood in place with his sword in his hand, and said with a smile: "But how can you know if you don't try things in this world......