Control over the mind.
This was a magic or an ability that Masa always honed as it was too troublesome to fight. He loved peace. Thus, he decided to control those who were at the top, like how Masa of Mahouka controlled many people with a high status in the world of Mahouka.
By manipulating the bio-electricity in the brain of his target in a delicate way, he could control nothing. If they somehow had some resistance, then he would just increase his energy until their resistance was no longer there, and they would be under his control.
Frankly, this method could also be used in the world of Fourth Masa, but as the opponents of Fourth Masa were too weak and were all normal humans, it would be too boring to do so.
The only problem was the world of DxD as the opponents of Masa of DxD, many of them, could destroy the world and universe with ease. Issei aside, many gods in the mythologies, especially the famous ones, were crazily powerful, and as he had read the story of DxD, he also knew other universes also existed, and the power of the creatures in that universe was just too... overbearing. At the same time, many of those figures had powerful mental resistance or even immunity, which made it even more troublesome or made them powerless despite how much energy they possessed due to the power of "Star Rage."
However, the world of One Piece is different since its focus is on physical ability. At the same time, they were all silly or even idiotic. The Haki, especially the Supreme King Haki, might be able to stop Masa's bio-electricity manipulation, but even so, it didn't mean they were immune since as long as Masa pressed further, they would be controlled by him.
To show that the mind manipulation ability was omnipotent in the world of One Piece, he would use Patrick Redfield as an example.
By using his Observation of Haki, Patrick could read the minds of others, and Luffy, who was the protagonist, had no resistance toward it. Similarly, the others also couldn't do the same, especially when all of those people focused more on the development of physical ability, and if someone could do it, then Masa could only think of Shanks.
Shanks might not have a special physical ability or even the power of Devil Fruit, but even so, his mastery over Haki was one of the highest, as not only could he see the future, but he could even use Haki to erase his presence. When he combined his swordsmanship with the power of his followers, he was a nightmare to many.
Kaidou, Whitebeard, and Big Mom might be able to hold Shanks and wouldn't lose, but they were sure that all of their followers would be dead, killed by Shanks. Thus, it was why Shanks became the Four Emperors.
In conclusion, a supreme physical ability wasn't the only way for one to become stronger, and Shanks showed that, but unfortunately, this guy was too obsessed with Gold Roger and the prediction of history, the "Will of D," and many others as if everything was predestined and nothing could go against the destiny.
Still, Masa didn't think that destiny was predestined. Instead, if one wanted to change their future, they would do their best since a future had never been static. If he had to say, a future was like millions of branches over a tree, and each of someone's decisions would lead to a different answer.
His will was to control this world so he wouldn't waste his time, and he said, "Bring me to Imu."
"Yes, Masa-sama." 5x
The Five Elders were submissive and ready to give their everything to Masa. If Masa told them to die, they would die without hesitation, showing their undying loyalty to him. If Masa wished to, then they could even destroy this world.
Regardless, as Masa wished for the crown of this world, they would lead him and bring him to Imu.
Soon after, Masa met Imu.
"What are you... who are—"
Bzzt!
As his power worked once again, Imu fell, but Masa ignored Imu and walked toward the Empty Throne. It was said no one could sit on that throne as this world couldn't be owned by a single person, but the truth is that it was owned by this immortal, Imu.
Several old swords and other weapons were stuck nearby, showing the original numbers of the World Government, but the one that attracted him was the large throne that stood majestic and immense, suitable for one who would control this world.
Before, it was Imu, but now, it is him.
As for Nika?
As Masa sat on his throne, the Five Elders and Imu kowtowed before him, the Lord of this world, the one who owned everything, whether it was on the earth or heaven above. The trip took a while, but even so, he had to say, his hard work paid him, or rather, if he couldn't achieve this, he would shame other Masa.
"Masa-sama!" 6x
The six of them gave their highest respect to the new conqueror of this world.
Yet, for Masa, this was just the beginning since after this, it would take time for him to stabilize his rule, but then again, it was just a time before everything was under his control.
"Nika..."
Like Nika, who loved to laugh no matter how tough the situation was, Masa also wanted to laugh at Nika's silliness since a loser had always been a loser.
At the same time, did it have to be Nika who saved this world?
If Nika and Imu could be the ones who controlled this world, then why couldn't it be Masa?
He thought so and had made up his mind, and then it was the turn of Masa of DxD to control his own world.
Sitting in the majestic hall that was located in Lucifaad, the original Capital of the Underworld, it was those important devils from the Great King Faction or the Four Great Devils gathered together, including Serafall, Falbium, and Ajuka.
As for Sirzech, his situation was unknown, but Ajuka planned to tell him about his problem later.
However, their purpose of gathering together wasn't due to Sirzech or Zekram Bael, who was sleeping due to the sudden "Sleeping Disease," which they caught instead under the lead of the new strongest devil, Masa Vapula.
"Let's start to talk about the peace of the three factions."
Yes, whether all of them should hold each other's hands and reach peace with the angel and the fallen angel.
This was the reason why all of them gathered together.