Hearing Marco's words, the captains looked at one another in confusion. Kingdew was the first to speak up.
"You mean improving our strength through Devil Fruits?"
There were indeed several Devil Fruits within the Phoenix Pirates at the moment, but none of the core members were particularly interested in them. Even though they all understood how much power a Devil Fruit could grant, none of them wanted to become landbound.
Those who desired them lacked the strength to claim them, since Marco controlled their distribution.
Marco shook his head. "No, this is a different method. Eating a Devil Fruit can still be an option, but not the main one."
"What method then?" Ace asked, curiosity in his voice.
Marco did not keep them waiting. "My Phoenix Fruit has awakened a new ability, I call it the Oath of Immortality. In simple terms, if I form a shared vow or contract with you, I can share the power of my Phoenix Fruit with you. You would gain its abilities."
The crew froze.
"Oath of Immortality?"
"It can give us the Phoenix Fruit's power?"
"How is that even possible?"
Disbelief spread through the group.
Jinbe spoke carefully. "Something that grants such power must have conditions."
Marco nodded. "Of course it does."
He looked around at everyone before continuing. "After forming a contract with me, you will gain part of the Phoenix abilities, mainly the regenerative flames. However, you will not obtain its destructive flame."
Blue fire flickered in his palm as he demonstrated.
"The drawback is simple. Once the contract is formed, I will create an Undying Heart using my ability. It will merge with your heart. At that point, you gain the Phoenix power, but your life will be tied to me."
The atmosphere grew heavier.
Marco's expression remained steady. "The immortality granted to the God's Knights and the Gorosei likely comes from Imu. That ability can grant immense power, but it also allows control over life and death."
He paused briefly before continuing.
"If anyone ever turns against me, like a second Blackbeard, I can trigger the Undying Heart within you. It will convert into destructive flames strong enough to erase you completely."
Silence followed.
Marco added calmly, "Think carefully. I will not force anyone."
For a moment, no one spoke.
Then Vista stepped forward.
"I accept."
His tone was direct. He was not a Devil Fruit user, and more importantly, he had no intention of ever betraying Marco. To him, this was simply a gain with no real loss.
Marco looked at him. "You understand what this means, Vista. Once the contract is formed, there is no turning back."
Vista smiled slightly. "Yes, I understand, Marco. Or rather… Marco-sama."
Marco's expression twitched slightly. "You do not need to add that."
Vista shook his head. "That will not do. If you are to become the king of this world, then proper hierarchy is necessary. Titles are unavoidable."
Many of the crew nodded in agreement.
Though they had once addressed Marco casually, his growing strength and influence had already changed how they saw him. Even those who had known him since childhood, like Vista and Jozu, could no longer treat him the same way.
Marco himself did not care much for titles, but he noticed the shift in atmosphere. Strength naturally changed relationships. It was simply how the world worked.
He exhaled slightly and raised his hand.
Blue flames gathered and compressed, slowly forming into a solid sphere of glowing fire. The energy within it pulsed steadily, as though it were alive.
Marco looked at Vista. "Do not resist. The Undying Heart will merge with your own. Your body will instinctively reject it at first, and there will be pain. Endure it."
Vista nodded firmly. "Understood."
Marco moved the flame sphere toward his chest.
The moment it made contact, Vista's body stiffened. A burning sensation spread through his chest, sharp and invasive, as if his heart itself was being set ablaze.
The pain expanded through his entire body in waves.
However, the Phoenix flames were not ordinary fire. Their regenerative nature prevented true destruction, allowing the process to remain within survivable limits.
Just as the pain reached its peak, the flames erupted outward from Vista's body, surging in bright blue bursts as the transformation began to take hold.