Riella’s father, Jonathan, was the previous commander of the adventure fleet.
An energetic man loved by all, many expected him to become a pillar of his fleet and Granvaloa as a whole.
The leader of the pirate fleet—the oldest of the four commanders—had even said that Jonathan deserved to become the next navarch.
However, an odd phenomenon had begun occurring about three months earlier—ships disappearing without a trace while navigating the South Sea.
It wasn’t just transport ships or merchant fleet ships either. Even military warships escorting them were vanishing.
That, combined with the change in the surrounding monster habitats, suggested to Jonathan that this was the work of a new monster that had claimed the area as its territory. It was the most obvious assumption. In this world, powerful monsters—mostly newly spawned UBMs—often had a profound effect on the ecosystems they entered.
In order to confirm his suspicions and solve the problem, Jonathan recruited the finest sailors the adventure fleet had to offer and went to investigate the South Sea.
He did all of this for the future of Granvaloa.
If this phenomenon continued, fewer ships would travel through the South Sea, which would greatly affect foreign trade—and to prevent this, they simply had to remove the root cause of it.
Preparing a force great enough to overcome even a truly powerful monster, Jonathan journeyed to the South Sea. With him were high-level tians, dozens of high-rank Masters, some of the best warships in all of Granvaloa, and even two Superiors with close ties to the adventure fleet.
They were enough to scatter hundreds of monsters and fell UBMs as powerful as Ancient Legendary tier, if not Mythical.
Jonathan was well prepared. He did all he could.
The only problem was...even all that wasn’t enough.
Ten days after they began exploring the South Sea, Jonathan’s forces encountered a singular, massive monstrosity. This was what caused all the ship disappearances, and it was indeed a UBM.
The adventure fleet engaged it the moment they spotted it.
Every ship unloaded everything they had at the creature. The warship artillery, the Embryo ultimate skills, and all the power of two Superiors were unleashed upon it.
However, it was all for nothing. The artillery, magic, Embryo ults—none of it had any effect on the UBM.
The adventure fleet was powerless against it, and the seemingly invincible creature killed and consumed them.
Even the Superiors they had counted on above all else were defeated.
With eighty percent of their forces gone, the adventure fleet had no choice but to flee.
Jonathan took up the rear guard to cover his comrades’ retreat, but the flagship—the Adventure—was sunk, and he was confirmed to have gone down with it.
This disaster had few survivors, but among them was Asam, who had served as Jonathan’s aide—and, of course, the Superiors and other Masters who eventually came back from the death penalty.
And with their return, they brought back the monster’s name—“Corpse Stronghold, Abyss Shellder.”
The leaders of Granvaloa instantly classified it as an extremely dangerous entity and forbade regular ships from entering the South Sea, preventing further casualties. In addition, they requested that Granvaloa’s seven Superiors—including the two who had accompanied Jonathan—go there and slay this UBM.
Months had passed since, and yet the Corpse Stronghold still controlled the South Sea.