One Piece: Kaido's adopted son, starts with the Eight Gates Formation.

Yamamoto's mouth gaped open, his jaw nearly dropping. Kyoraku's straw hat slipped. Byakuya's hand unconsciously reached for the hilt of Senbonzakura's sword.

Aizen—the man who betrayed the entire Soul Society, single-handedly challenged the Soul King Palace, and once instilled fear in the very bones of all Shinigami—bowed down before a three-year-old child.

"Young Master." Aizen straightened up, his ever-present smile returning to his face, but this time there was a hint of truth in it—something only he knew. "There's something I'd like to report first."

"explain."

"Yhwach—the Quincy King—he won't give up so easily. His goal has never been the artificial core itself, but rather the 'power of the Soul King.' The core, or the Soul King himself, are both his targets."

"I know."

"But what you might not know is—" Aizen lowered his voice, "his omniscience and omnipotence have a hidden function that even he himself doesn't fully understand."

Lynn's eyes narrowed slightly.

This was a rare instance of him showing "interest" in his eyes.

"What function?"

"When he was driven to the brink, Omniscience and Omnipotence automatically activated their 'final form'—merging him with the 'fragments' of the Spirit King. Although you released the Spirit King, his fragments scattered throughout the three realms—the Spirit King's left arm, the Spirit King's right arm—still exist. If Yhwach collects these fragments—"

Aizen didn't finish speaking.

He didn't need to finish speaking.

Lynn understood.

"You mean, he'll become stronger?"

"Not just stronger." Aizen shook his head. "He will become—a new Soul King. A Soul King with the full power of a Soul King, a Soul King with his own will. At that time—"

"He won't be fun then," Lynn said lazily.

Aizen paused for a moment, then smiled: "...Yes. It's not fun anymore."

Lynn took out the lollipop, looked at it, and then put it back.

"Then let's not let him change."

"The Spirit King's left arm is in the Shadow Realm. The Spirit King's right arm is—"

Do you know where it is?

"After being locked up for several years, I can't just do nothing." Aizen's lips curled into a slight smile.

Lynn jumped onto Kaido's shoulder and patted Kaido's head.

"Dad, there are still two parts to pick up."

"What part?"

"The arm of the Spirit King."

Kaido didn't understand what this was, but he didn't need to. His young master said to go, so he went.

Where?

Aizen stepped forward, a smile playing on his lips. "If the young master doesn't mind—I'll lead the way."

Kaido glanced at Aizen and narrowed his eyes.

He didn't like this person. Too slippery. Always smiling when talking, and you could never tell if their smile was genuine or fake.

But when the young master took him in, Kaido acknowledged him.

"Walk."

The group emerged from Avici Hell and returned to the surface of Seireitei.

The God-Slaying Island hovered in the air, its engine humming softly.

Aizen took a deep breath—he hadn't breathed outside air for years.

"That direction," he pointed east, "the Spirit King's left arm—the Silver of Stillness—is hidden by Yhwach deep within the Shadow Realm. And the Spirit King's right arm—the Right of Stagnation—is in another place."

"Where?"

Aizen's smile deepened.

"Hell. Not the Avici Hell—the real hell. The 'Hell Realm' of the Grim Reaper's world."

The expressions on all the Grim Reapers' faces changed again.

Lynn tilted his head: "There's another hell?"

"Yes." Aizen looked at Lynn, "Deeper, darker, and more dangerous than Avici Hell—the real hell. It doesn't hold criminals, but—"

He paused.

"—Monsters that even Death cannot kill."

"A monster?" Kaido's eyes lit up.

He has a natural and irresistible interest in the word "monster." After all, he himself is the world's strongest "monster"—Kaido of the Beasts.

"What kind of monster is it? Is it strong?"

Aizen glanced at Kaido, a smile still playing on his lips, but what he said next silenced Kaido.