Massacre at Katze Plains

Massacre at Kazte Plains was an event that took place during the Annual War between the Re-Estize Kingdom and the Baharuth Empire. It is also when the Ainz Ooal Gown and the Sorcerer Kingdom officially debuted themselves to the world.

Background
Prior to the massacre, the Baharuth Empire received word of a tomb that has mysteriously appeared within the borders between their nation and the Re-Estize Kingdom. The Empire has sent Workers to investigate the tomb and report back what they may find but they never returned. Instead, two Dark Elves appeared at the castle, revealing themselves to be members of the Great Tomb of Nazarick. After killing many of the Empire's men including one of the Four Imperial Knights, the Elves demanded the ruler, Jircniv Rune Farlord El Nix to come to visit the tomb and apologized to their king, Ainz Ooal Gown for the transgression otherwise the Empire will pay the price for refusing to comply with their nation's destruction. Jircniv and his entourage arrived at the Great Tomb where they encountered and taken aback by many of the strange denizens that lived there and the power they wielded. Ainz Ooal Gown, in particular, showed his ability to raise the dead and converted them into undead warriors with supernatural ease. In addition, he possessed a vast military force and beautiful women that will put all of the New World to shame. The Emperor seemingly accepted this and proposed to Ainz an alliance between their nations which the latter agreed but after Jircniv left, in truth, he has already deemed the Elder Lich-like being a threat not just to his Empire but to the entire world and planned on using their alliance to leak information to the other Kingdoms and unite them against him and using various schemes to undermine him. Unbeknownst to him, one of Ainz's men already deduced Jircniv's treachery and informed this to his king.

At the Re-Estize Kingdom, King Ramposa III and his court were informed about Ainz Ooal Gown's existence and his participation to the Annual Wars as an ally to the Baharuth Empire. Terms had been made that should the kingdom surrendered, they must offer E-Rantel to Gown. Despite Gazef Stronoff's warning them about the dangers of the magic caster, both the Noble and Royalist factions dismissed him with only the king and Marchioness Raeven accepting what the Warrior Captain has told them. Nonetheless, the kingdom refused to lose part of their land and decided to continue the war by conscripting many of their male citizens to counter Ainz Ooal Gown.

Following this, Gazef met up with Brain Unglaus and Climb. Gazef asked what the two had been doing throughout the day. Brain and Climb explained that they traveled to E-Rantel in hopes to meet Momon and discuss about the two vampires he was hunting. Unfortunately, he wasn't there as he was taking on a high-rank request much to Gazef's disappointment who thought that the Raven Black Hero can be of help to repel the Empire and Ainz Ooal Gown. During their conversation, Climb informed them that he will be wearing his usual armor despite the obvious disadvantages it presented under orders of his mistress, Princess Renner who was secretly working with Ainz to spare the young knight from harm. Gazef gave the same advice he said to the court about Ainz Ooal Gown to his comrades and the two will made sure to prepare themselves whatever would throw at them by the man who saved Gazef's life. Gazef then mused to them that should all three of them survived, they should have drinks. Meanwhile, King Ramposa had sent his son, Barbro to head to Carne Village. The reason for this was to gather information about Ainz so that the Re-Estize Kingdom can offer a peaceful resolution to the man and Ramposa secretly wanting to spare his son from death. This action proved fatal as Barbro disobeyed his father and had the village be attacked by his men so that he could use the people as hostages to have Ainz surrender. The people of Carne Village are understandably angered at this and chose to fight on behalf of the magic caster who was their savior, summoning the Goblin Army that wiped out many of their enemies. Barbro and his men retreated in terror. Later that night, Lupusregina Beta visited Barbro who begged to be spared but this is met with deaf ears as the Battle Maid explained that her king has deemed the First Prince useless to his plans and must be punished for his actions. Goblins slaughtered what was left of Barbro's army and the prince died thirty minutes after Lupusregina tortured him. At the Imperial Castrum, Nimble Arc Dale Anoch and the Imperial Knights awaited for Ainz Ooal Gown's arrival, under secret orders by Emperor Jircniv to spy on the magic caster and determine his power. Piecing together what he had seen, the Emperor believed that Ainz Ooal Gown can at least kill a thousand men and using that theory, he decided the best course of action is to request Ainz to use his strongest spell and show the world the threat that he posed. After that, Nimble and the Imperial Knights will push away what remained of Re-Estize's army. Ainz Ooal Gown finally arrived along with his escort, Mare Bello Fiore. Ainz was also eager to follow Jircniv's suggestion. His main goal was to learn the existence of other Players like him and hopefully, one might be his comrades. He will reveal himself out in the open all while performing the spell. This tactic is to draw out anyone who recognized the spell and deploy the right countermeasures to prevent it. That will confirm Ainz's questions. After greeting his allies, Ainz ordered his army to come and much to the Imperials' shock, the army was comprised of Death Knights and Soul Eaters, monsters in legends that have wiped out entire countries.

Battle
The Annual Wars has begun. The Re-Estize Kingdom arrived on the battlefield, bringing in their Royal Army comprised of 245,000 soldiers. On the side of the Baharuth Empire, they had brought six legions of the Imperial Army to confront the opposing side. The only one who has yet to appear was Ainz Ooal Gown.

Returning to the Re-Estize Kingdom, King Ramposa III was conversing with the nobles who believed that with their sheer numbers, they have a significant advantage over the Empire and will obtain victory. This mindset also extended to the commanders such as Marquis Boullope who commanded the left wing of the Royal Army. While glad that morale is high, the king isn't fully confident about the situation.

At the front, Gazef met up with Marquis Raeven who had his team of Ex-Adventurers as his bodyguards. The two noticed that the Imperial Army has yet to make a move against them which was unlike them during the past skirmishes. Gazef believed that it was because of Ainz Ooal Gown. Raeven then noticed that Gazef was wearing four of the five National Treasures of the Re-Estize Kingdom consisting of the Gauntlets of Vitality, Amulet of Immortality, Guardian Armor and Razor Edge. Gazef explained that King Ramposa ordered him to wear them despite how he felt about this and how this would affect the nobles later on. Raeven understood that this decision was born from Gazef's warnings and Ramposa was taking precautions in case the magic caster was just as powerful the Warrior Captain claimed him to be. As they are discussing what the Imperial Army and Ainz Ooal Gown have as trump cards against them, both came to an agreement that they must survive this battle, with Raeven intending to return to his wife and son. Just then, the Imperial Army started to move. They were not attacking but merely moving aside to allow the main doors of their base to Imperial Castrum. Once they did, monstrous creatures began to march out of the base. The Royal Army were at lost for words as they stared upon 200 Death Knights and 300 Death Warriors, all mounted on the giant skeletal horses, Soul Eaters. The Empire were trying their best not to panic as their fear has been building up ever since these new forces arrived. The Ex-Adventurers reunited with Raeven and informed him about the Soul Eaters' identity and the dangers they pose. Most of the Royal Army began to realize the magnitude of the truth behind Gazef's words but it was a short time as, after the army of the monsters, three people were the last to exit the Imperial Castrum; Nimble of the Imperial Knights, Mare the Dark Elf and the Sorcerer King, Ainz Ooal Gown.

Gazef muttered Ainz's name allowing Raeven to now know who the magic caster was. Ainz and his escorts stepped toward the front lines. Once they halted, large magic circles started to appear around them. The Royal Army were surprised once more, having not seen such magic of this scale. Raeven and the Ex-Adventurers returned to their unit, deciding that the battle was already lost. Gazef stayed behind to protect King Ramposa and the Royal Army from the attack. However, Marquis Boullope foolishly led the left wing to charge at the Imperial forces. Ainz looked on at the Royal Army and their scared and confused reactions were enough to confirm to him that there are no other Players present. He had already prepared a Cash Item to accelerate the process of his super-tier magic. Looking back about his plan, Ainz had thought about the massive casualties that was about to take place but he truly felt nothing about it, whether it was because held no personal attachment to most of Re-Estize or his time with Nazarick and this world has started to take affect on him. Still, his mission was there. He has to take action to allow himself and his tomb to prosper. Crushing the Cash Item in his hand, Ainz Ooal Gown unleashed the super-tier magic spell 'Ia Shub-Niggurath'. A dark wave burst forth and headed toward the Royal Army's left wing. In an instant, the wave killed Boullope and his men whose corpses fell to the ground.

Both the Re-Estize Kingdom and the Baharuth Empire stared in horror at what remain of the former's left wing. Ainz noticed Nimble's look of fear and asked if anything was wrong. Nimble calmed himself and explained that he was surprised how effective the super-tier magic spell was, killing 70,000 men in matter of seconds. Deep in his mind, Nimble dreaded what would happened if Ainz unleashed his might onto his nation. Suddenly, Ainz laughed at that statement. Nimble turned around and apologized, hoping he did not offend the Sorcerer King. Ainz corrected Nimble that the event that he watched was only part of the spell. The spell required sacrificial offerings as fuel to complete it. Now that it was done, the real spell was about to start much to Nimble's growing fear.

Up at the clouds, a black sphere appeared above the corpses of the left wing. It dropped onto ground and began consuming all of the bodies. When it was done, taking its place were eldritch abominations that looked like black mass with elephant-like legs, human-like teeth and dozens of tentacles covered over their bodies. Ainz revealed to his allies that they were called Dark Young and he was surprised that he has summoned five of them, an achievement surpassing the one that has summoned two. Only Mare truly praised his king while others tried to hide their discomfort. Satisfied that he has achieved such an momentous accomplishment, Ainz decided not to send them away and had ordered the Dark Young to attack the Royal Army but spare four individuals their master has selected. The Royal Army were ordered to ready their spears and attack the Dark Young although most were in paralysis upon seeing the beasts, refusing to believe that such things existed. When the Dark Young arrived, what was once thought to be a battle turned into a massacre. The Dark Young used their massive hoofs and tentacles to wipe out hundreds of the soldiers. The surviving commanders ordered a retreat with the soldiers complied without question but all proved to be futile. The bloodcurdling screams were everywhere followed by the sound of an impact that caused body parts exploding that can only be described as "Splat!". This was a process repeated over and over again across the battlefield.

Marquis Raeven ordered his men to retreat before he and his team of Ex-Adventurers fled as well. Raeven could only curse himself for not realizing enough the power of Ainz Ooal Gown who he deemed a monster that must be stopped otherwise the future of Re-Estize will fall apart. Then, one of the Dark Young started following them. Left with no options, the Ex-Adventurers stayed behind to fight it and sacrificed themselves to allow a regretful Raeven the time to escape its pursuit. Unknown to Raeven and the fallen men, Ainz had ordered the Dark Young to spare the marquis from their wrath.

The Empire watched the slaughter, trembling in terror. They no longer cared that the Re-Estize Kingdom was their enemy and only begged all of them to escape. Ainz declared the charade was over and the Empire turned to him as he revealed his true skeletal appearance. This frightened them as they now realized they had just affiliated themselves with an inhuman being. Ainz demanded applause for his might that he brought upon the Katze Plains. Mare clapped in ecstatic joy for his king and soon, the Imperial Army joined as well.