Start by Eating Jake Jake no Mi

Demonic Power. 

This was the source of the power of every devil. 

Rather, energy was the source of power for every living being. 

If Sirzech didn't have ten times the Demonic Power of the Lucifer, even if he had the power of destruction, he was nothing. It was because of his Demonic Power that he could be called the strongest. 

Unique abilities, power of destruction, and many others. 

If their opponents had an abundance of energy, then the effect of their abilities would be negated. 

So—

"How?!" 

As Sirzech held his wounded body that was on the verge of breaking apart after being blasted by Masa's punch, he couldn't help but exclaim in shock and dumbfoundedness as he saw Masa's energy growing stronger and stronger! 

No, Masa's Demonic Power grew to about the same level as him! 

Yet, how? 

The demonic power of every devil was innate, and it was impossible to increase no matter how they tried. 

This was also the source of Sirzech's confidence since Masa's Demonic Power was far lower than him, yet why did Masa's Demonic Energy increase?! 

Naturally, as Sirzech was curious, the others were also curious since Masa's Demonic Power increased to the amount that they could only feel awe!

So, when all of them waited for his answer—

"Idiot! Do you think I will tell you?" 

"...." 

Sirzech frowned as he tried to recover, and at the same time, he also viciously said, "As expected, you are dangerous! You must gain that power from a dangerous source!" 

"Well, aren't you the same? I think that you are not even a devil! You are a monster who took over the child between the Lord Gremory and Lady Gremory!" 

If Sirzech was vicious, then Masa was simply evil since he simply directly told Sirzech that his race wasn't a devil, but something else and an anomaly!

"...." 

Sirzech was dumbfounded, then got angry, "YOU BASTARD!" 

"What are you getting angry for? Is that the truth? Are you really taking over the child of the Lord Gremory and Lady Gremory? How scary~!" 

Masa snickered and said, "If you can't talk, then just shut up." 

Sirzech's talent at trash talking was simply shit, so Masa simply destroyed him. 

"Still, I am in a good mood, so I will tell all of you." 

Masa smiled, causing everyone to feel speechless. "Have you heard of nuclear fusion?" 

"...." Everyone. 

"As expected, you are an idiot." 

"...." Sirzech. 

"Nuclear fusion is the process that powers the sun and other stars. In the sun, nuclear fusion occurs when hydrogen atoms fuse together to form helium, releasing energy in the form of light and heat." 

Masa appeared proud and said, "And all I do is mimic that process!" 

By taking in the molecules in his surroundings and mixing them with his Demonic Energy, he then collided them together in a process similar to nuclear fusion to create more energy.

This allowed his energy to increase dramatically, and no matter the consumption, it would not decrease and allowed him to fight without running out of energy almost indefinitely.

Now, how can he do this? 

It was all due to the power of Baku Baku no Mi, Yami Yami no Mi, and Ton Ton no Mi. 

By combining the ability to devour from the Baku Baku no Mi, the attraction ability of the Yami Yami no Mi, and the gravity-like power of Ton Ton no Mi, Masa could recreate how a star gained its energy! 

In the past, he might not have used this since it meant that he would cause a severe depletion of the planet's or the Underworld's energy, but he had a solution for it, especially when he could gain the molecules from various sources due to the Wapu Wapu no Mi, he had nothing to hold back! 

Yes, Masa knew that his Demonic Power was far lower than Sirzech's, but even so, he had a way to fight it! 

"So, as long as this universe exists, I won't die! 

"This is my ultimate ability!" 

"Star Rage!" 

At that moment, everyone was in a daze, and Falbium couldn't help but turn his gaze to Ajuka. "Isn't he like you, Ajuka?" 

"Yes... he is like me..." Ajuka felt conflicted since he could tell that Masa developed his ability in a similar way to him. 

Still, if Ajuka used the power of mathematics, Masa used the power of physics. 

By mimicking the feat of the star to gain its energy, Masa became a star. 

So, could Sirzech defeat and annihilate the star? 

The answer was obvious—

No! 

By then, it was no longer a fight between them, but it was a one-sided beating as Sirzech was beaten by Masa mercilessly. 

The figure of the proud Lucifer was no longer there, and all one could see was a loser who was beaten up. 

More importantly, due to the Armament Haki, which made Masa able to bypass the power of destruction and the power of Yami Yami no Mi that was able to nullify Sirzech's power, all Sirzech could do was wait for death, especially when Masa kept devouring Sirzech's Demonic Power. 

In the end, even if Sirzech was able to manipulate the concept of elimination, Masa could also manipulate the concept of devour, darkness, and many others. 

Naturally, Sirzech's concept of elimination was powerful, but as expected, in the end, everything was determined by the energy they possessed! 

The biggest was the strongest! 

So, Masa was the victor of this duel! 

"You like to erase your opponents, right? Then, let me erase you." 

Masa didn't care about the consequences of erasing Sirzech, especially since Sirzech had wanted to kill him before. 

As the magic circle was formed, a blue brightness radiated on the sky, then—

"Dominator." 

However, when the blue light was about to fall onto Sirzech, it changed its trajectory to the side and erased the environment. 

Yet, those who saw the effect of that blue light all shuddered, watching everything collapse, making them realize that the young man had already become the strongest devil in the world. 

Still, Masa looked at the figure that helped Sirzech, standing quite far away but using his power to change the trajectory of his "Dominator." 

"...please stop looking at me like that." 

Facing Masa's silent stare, Ajuka was helpless and said, "It's just a duel, right? There is no need for you to kill him since it will affect the overall power of us, the devil. Moreover, you don't have an intense hatred for Sirzech, right? Isn't this enough?" 

Masa didn't say anything for a moment and observed his surroundings. Nodding, feeling satisfied that only Ajuka was the one who moved, but then again, all of them knew well that their standing was no longer the same as his, and at this moment, he had stood at the highest hierarchy of everyone. 

"You are right. For the overall strength of the devil, his strength is needed. Thank you for stopping by, Ajuka. Though, I am sorry for thinking of killing you too, before." 

"No problem, and I am sorry for stepping on your fight with Sirzech." 

The two smiled at each other, and even Masa called him by his name directly, Ajuka only smiled no matter how rude it was. 

Still, Masa sent a virus to Sirzech as he walked away since he was already bored. 

Watching Masa, who had left, Ajuka sighed in relief, then felt helpless, especially when his ability didn't work in a way that he calculated, but it was all ended before he looked at Sirzech, who had passed out. 

"You owe me one." 

At the same time, Ajuka also knew that he owed Masa a lot of things, which made him feel helpless. 

Still, as Masa returned, everyone welcomed him excitedly, as if he were the victor. 

"Masa!" 

"Masa-sama!" 

"Congrats!" 

Only Issei was in his deepest despair.