Quagoa Genocide was a mass execution against the United Quagoa Clans carried out by the Sorcerer Kingdom. It was ordered by Ainz Ooal Gown and carried out by Shalltear Bloodfallen and Aura Bella Fiora.
The United Quagoa Clans having been formed through the efforts of its revolutionary leader, Pe Riyuro, had claimed the ancestral city of the dwarves, Feo Berkana as their own. The Quagoa seeking to claim the entire Azerlisia Mountains and monopolize the ores for themselves, aimed to wipe out the neighboring Dwarf Kingdom.
To accomplish this Pe Riyour planned a massive assault on the last city of the dwarves, Feo Jera. The Great Rift, was primarily an obstacle for the Quagoa to cross and the only path across was a rope bridge guarded by a dwarven fortress.
However, somehow the Quagoa managed to locate an alternative route around the Great Rift, allowing his warriors to stage an attack on the fortress taking the soldiers stationed there by surprise.
After securing the bridge, the Quagoa marched to the next stronghold guarding the entrance to the city. The soldiers of the Dwarven Army were unprepared by the demi-human force but managed to hold off the mob back and shut the gates.
However, for the demi-humans adapted to subterranean environments, it was only a matter of time before they dug through the gates. Pe Riyuro intended to ensure the extinction of the Dwarves sent another force of Quagoa at the abandoned city of Feo Raizo to kill any dwarf who tried to find refuge from the doomed Feo Jera. By chance, a delegation from the Sorcerer Kingdom was in the area of Feo Raizo, seeking to establish diplomatic relations with the Dwarf Kingdom. Locating a lone citizen, named Gondo Firebeard they also intercepted the Quagoa sent to the city as scouts.
The Floor Guardian, Shalltear Bloodfallen apprehended them and after interrogating the demi-humans learned of the United Quagoa Clans plot. Ainz Ooal Gown believing that this information would maximize the gain with the dwarves hastily journeyed to Feo Jera above ground. Approaching the gates of the surface fortress, Ainz and his entourage were met with wariness due to him being an undead. However, Gondo and the threat of the Quagoa at the dwarves' doorstep were enough to convince the Commander-in-Chief of Ainz's sincerity. Faced with the threat of the demi-humans, the commander acquiesced for Ainz to provide aid to lift the siege of the fortress. Summoning two Death Knights, Ainz sent lose upon the Quagoa force.
The undead chased the Quagoa into full retreat across the bridge, however, they fell into the Great Rift after the Quagoa commander, Yozu, cut the lines to the rope. After Ainz had successfully repelled the demi-humans he was permitted to have an audience with the Regency Council. During the negotiations, the two nations agreed to open relations with each other, though the perquisites were for Ainz to reclaim the city of Feo Berkana and eliminate the threat of the Frost Dragons and Quagoa.
The Sorcerer King reaching Feo Berkana sent his two followers: Shalltear and Aura Bella Fiora to deal with the Quagoa problem. Ainz gave the two of them the order of confronting the Quagoa and having them submit to his rule. However, if they dare to refuse his offer or pledge their loyalty to the Sorcerer King, then Ainz expects the two to intimidate the Quagoa with their own hands. Knowing that the United Quagoa Clans numbered 80,000 and the limited resources of Nazarick not being sufficient for them all, Ainz also ordered the two Floor Guardians to cull their numbers to 10,000 should the demi-humans refuse a surrender. Outside of Feo Berkana, Aura activates her World Item known as Depiction of Nature and Society to completely trap the Quagoa from ever escaping until they're captured.
The army of 60,000 led by Pe Riyuro was confident that they would be able to stand up to any opposition. Then, two figures appear before them. Having known of Yozu's encounter with the Death Knights, he approached the two warily. Shalltear and Aura give him an ultimatum and declared that they had been sent to let the Quagoa know that they were to be taken to the Sorcerer Kingdom.
However, only a number of 4,000 each from the male and female population and 2,000 children would be given such privilege while the rest would be eradicated. Pe Riyuro instinctively knew this was neither a bluff nor the words of madmen but still cautiously asked for proof of their strength.
The two Floor Guardians took this as a refusal and soon afterward, the genocide began. Each of Shalltear's strike sent tens of Quagoa flying through the air, their bodies torn to pieces and their flesh and blood rained down on the nearby Quagoa. Trapped inside an unknown dimension and facing an enemy none of the Quagoa could hope to win against, Pe Riyuro gathered all the Red and Blue Quagoa and sent the elite troops into engaging the overpowering enemy with a heavy heart. Watching his troops being cut down, he sent another order to the rest of his troops; select two thousand from their children and kill the rest in order to spare them a quick death.
When they had gone to carry out his order, Pe Riyuro broke down in tears as he, who had been revered as the greatest king of the race, bore witness to the greatest genocide of his people, but his wailing and cry of despair are drowned by the screams of death coming from the executed children.
The genocide was the greatest holocaust subjected to the Quagoa race. The entirety of the United Quagoa Clans was almost wiped out, with less than 10,000 individuals left of which 4,000 were males, 4,000 females, and just 2,000 children. The entire race was relocated to the Great Tomb of Nazarick from Feo Berkana and became subservient to the Sorcerer King.