Under Ace's control, the burning pillar of fire contracted to the limit, and finally the diameter stayed at half a meter in diameter and three meters in height, and the center of the flame also changed from dark red at the beginning to dark red.

Elementalized Ace stood in the center of the pillar of fire, and after feeling that he could no longer shrink the flames, he began to feel the temperature around him.

"600 degrees, a little bit higher, it seems to be the limit." Feeling the temperature of the surrounding flames, Ace dispersed the flames around him, and felt a little disappointed in his heart.

"Try again!"

"Flame Ring—Pillar of Fire!"

The great pillar of fire then burned, then began to shrink, then extinguished.

"Come again!"

"Flame Ring—Pillar of Fire!"

Rumble!

……

Jetting, compressing, and burning over and over again the flame of the fruit is changed in various forms, but the temperature of the flame always stays at 600 degrees.

"Whew~Whew~! Is this the limit? After a violent gasp, Ace sat down on the ground exhausted, his face unconcealed with disappointment.

The flame of 600 degrees seems to be the highest temperature flame he can burn at present, but this temperature is far from enough for him.

"Bastard, why is it only 600 degrees, and there should be no upper limit to the temperature of the flame burning in theory, is it true that the upper limit of the flame burning the fruit is only 600 degrees? At the very least, it needs to reach a temperature similar to that of lava! Ace gritted his teeth and said unwillingly.

Over the next few days, Ace tried his best in all his ways, but he elementalized the burning flame, which remained at 600 degrees Celsius, and could no longer be raised.

"No wonder Akaiu would say that there is a suppression of the upper position and the lower position of the magma fruit and the burning fruit, if the upper limit of the burning temperature of the burning fruit is only 600 degrees, it will indeed be suppressed by the magma fruit, if this upper limit cannot be broken, then when you encounter that red dog, you can only run away." touched the upper limit of the temperature of the flame that burned the fruit, which made Ace depressed, "No wonder Ace will develop so many inexplicable moves in the original book, it is estimated that he has also touched this boundary, and there is no way to develop the ability to burn the fruit in another direction." ”

"In the original book, the guy who ate the hot fruit developed the highest temperature seems to be 10,000 degrees, why is the upper limit of burning the fruit only 600 degrees? So depressed. ”

"But think about it, after all, it's not a temperature fruit, if there is no upper limit to the flame temperature of the burning fruit, then the name of the strongest devil fruit in history is nothing else, remember the highest temperature studied by humans on the earth in the previous life, it can reach hundreds of millions of degrees, which is many times higher than the temperature of the core of the sun, if the flame temperature of the burning fruit can be increased infinitely, not to mention reaching hundreds of millions of degrees, even if it reaches the temperature of the sun's surface, it is enough to destroy the world instantly."

"Since the temperature development of the burning fruit has touched the upper limit, there is no way but to develop it in another direction, at most make some other preparations, and when you meet that red dog in the future, it will be good to give him an unexpected gift." Ace thought.

After this period of development, he almost determined that the maximum upper limit of the flame temperature of his elementalization was only 600 degrees, and he didn't think of a way to break this boundary for the time being, but there were still many ways to increase the temperature by adding something to the burning flame.

However, this method of relying on foreign objects is never safe, and it is still necessary to find a way to break the boundary of burning fruits.

"So...... Now, let's get some practical moves, well, try this. ”

"Wow!" Ace raised his hand, and a fireball with a diameter of half a meter appeared in his hand, and then he concentrated and began to compress the fireball in his hand, and after a while, the diameter of the fireball was compressed by Ace by ten times.

"Fire Bomb!" Ace threw the tenfold compressed fireball in his hand forward.

Rumble!

After leaving Ace ten meters away, the fireball exploded suddenly, instantly blasting the ground into a large crater several meters in diameter.

"Half a meter in diameter, the five-fold compression time is three seconds, the tenfold compression time is seven seconds, the tenfold compression time is not bad, but the time is a little long, try again."

Seven seconds doesn't sound like a long time, but in a fight against a strong opponent, seven seconds is enough to kill an enemy several times, and no one would be stupid enough to stand there and let you brew a big move.

"Whew!" Another half-meter diameter fireball appeared in Ace's hand, this size of the fireball was the maximum amount he could release instantly, and then under Ace's control, it began to compress, and then exploded.

Over the course of three days, Ace tried to compress the flame as much as possible, and finally the time to compress the flame was reduced tenfold to one second, and if it was compressed five times, it would only take one-third of a second.

"Whew~, it seems that it will take longer to train from the release of the flame to the completion of the process of compressing the flame to make the flame bomb in one go." Looking at the large and small potholes on the ground, Ace couldn't help but show a smile on his face, the development effect of the flame bomb is very good, although it can't be instantaneous, but the one-second compression process can already be used as a killer feature, and as long as he continues to develop in this direction, it is just the process of compressing the flame or the power of the flame bomb, it can be continuously improved.

"Let's try another move." Ace said, with a look of eagerness on his face, and a large amount of flames suddenly ignited in his right hand, and Ace held the palm of his hand, and the burning flames suddenly condensed, changing into the appearance of a long sword.

"Ha, I didn't expect flame shaping to be so simple." Looking at the flame sword in his hand, Ace's eyes lit up with excitement, "Well, you have to take a domineering name, what's it called?" ”

"Fire sword?"

"Emperor Yan Sword?"

"Evil King Flame Killing Sword?"

"Well, let's call it this, and the way of appearance should be adapted!" A smile appeared at the corner of Ace's mouth, and he suddenly thought of a domineering name.

"Everything is dust—a blade like fire!"

Ace held his right hand weakly, leaning on his left palm, and then slowly moved away, and a long sword with condensed flames slowly appeared, as if it was drawn from his left palm.

"Well, sure enough, it's much more domineering to shout out!" Looking at the flame sword in his hand, Ace said with satisfaction.

"And one last resort!" With a flick of Ace's arm, the flame sword in his hand dissipated, and then he looked up at the sky, and at the same time, Ace's legs suddenly elementalized.

"Stormfire!"

"Boom!"

In the deafening roar, the elementalized flames of Ace's legs suddenly turned into a jet state, and the next moment, his figure suddenly roared up from the ground and soared into the sky!