"Massacre" (大虐殺 Dai Gyakusatsu) is the twelfth episode of the Overlord III adaptation. It was first broadcasted on September 25, 2018.
Jircniv receives word from Re-Estize that they will commence with the annual war, as the allotted time for them has passed. When Baziwood mentions that with Ainz's participation, the Kingdom's army doesn't seem like much; even as Ainz will be using one of his strongest spells. Jircniv wants that outcome, as if an alliance against Ainz Ooal Gown is to be successful, then the world must see his potential. Considering how a lone dark elf killed a hundred soldiers in an instant, theoretically Ainz can kill 2000-3000 soldiers in a single spell; shocking Baziwood and the scribe in the room. Baziwood even affirms that not even the Evil Deities or the Thirteen Heroes could perform such feats. Jircniv assures them this is a better course, as seeing his power can better give them a means to counter him.
As the Re-Estize Army stands ready, Marquis Boullope is tensed to find out that the Imperial Soldiers haven't attacked yet when they normally start the fighting. Questioning a soldier on Prince Barbro's status, all they know is that he should have reached Carne Village yesterday afternoon. Dismissing that to focus on the now, Boullope orders 70,000 men on the left flank to ready for attack. Further back at the frontlines, the nobles inform King Ramposa III that they hold the advantage of 240,000 men to Baharuth's 60,000. Believing themselves unstoppable now, they laugh and even thought of invading the Empire itself. King Ramposa III is pleased to see the morale is at its peak. Back to the frontlines, Marquis Raeven and Gazef have a talk about the Imperials not attacking. While Gazef sighs over not having the battle, Raeven notes that he's equipped with the four national treasures. Gazef finds joy in the trust the king shows by letting a commoner like Gazef be entrusted with such things. Marquis Raeven also takes attention of the King's trust of his son Barbro, by sending him away to Carne Village to keep out of the fighting, after King Ramposa took Gazef's warning of Ainz quite seriously. While Raeven would have raged on Barbro's ignorance, as a father he understands Ramposa's choice. In this instance, Gazef and Raeven share an understanding of each other in mutual respect. Raeven plans to spend time with his son after the war and knows full well Barbro cannot understand his father's feelings; finding it to be sad. Upon seeing the Imperial troops move in formation, Raeven and Gazef turn their attention.
A drawbridge lowers the gate, with Death Knights leading a procession; sending fear through the Imperial soldiers. A masked Ainz exits the Fort, and stands front at the center, as Gazef confirms to Marquis Raeven that is the same man he spoke of. As soon as Gazef tells Marquis Raeven to call for his Adventurers, they already arrive to ask if the Marquis sensed the level of magic as well. Ainz uses an encompassing magical seal, large and bright enough to be seen by all in the plains. Marquis Raeven in confusion by what they are to battle, asks Gazef to protect the King while he returns to his troops. The Marquis orders a dispersal of troops in case Ainz will use a wide-reaching spell.
Ainz observes and notes that, while back in YGGDRASIL magic casters with higher magic were targeted first. He concludes that there is no player on Re-Estize's side, and after pulling out a cash shop item, he will feel nothing for the deaths of anyone, stating he will have fun. Seeing the Royal Army charge and wishing to bring more riches to Nazarick, Ainz crushes the cash shop item and casts Iä Shub-Niggurath. Just then, the charging forces keel over after being hit by the spell, with both sides looking in pure shock. Ainz asks a panicked Nimble what is wrong, for him to say the spell was impressive to sweep 70,000 troops. Ainz laughs, scaring Nimble, but the Overlord confirms the use of "was" is not right as the spell is still ongoing: the offering to the mother goddess of the black harvest, so as to summon her Dark Young.
Just then, a massive black sphere appears above the sprawled out dead, and morphs into a black liquid consuming the bodies. Ainz then decrees for the great despair to start. With that, five hideous tentacled maws on five-legged pitch-black goats rise from the ground. Ainz laughs in joy, having reached a new record for being the first to summon five Dark Young. Mare congratulates him, and Nimble does so hesitantly; oblivious to the Imperial Soldiers shaking in fear. Not wanting to waste a temporary summon of such magnitude, Ainz orders the Dark Young to attack, with the Royal Army scattering in pure terror; however, Ainz does invoke that there are four individuals they are not to harm.
At the frontlines, a soldier asks if this is all just one horrible dream, only for the Dark Young to trample them. Seeing the horror, all the soldiers run for their lives, with Marquis Raeven and his adventurers running as well. As Marquis Raeven thinks of returning home to mount a counter to a monster like Ainz, Lockmeier and his group opt to delay the charging monsters behind them to allow Raeven to escape. Thankful, he does not waste their sacrifice and continues on, even when hearing each of them die. While on the other side, an Imperial soldier states that this is no longer a war, and it is then Ainz removes his mask and gloves to reveal that he is an undead. He demands for them to praise the work that he has achieved with ovation; they clap slowly but increase the pace when a Dark Young approaches. But when it is close enough, the troops run in panic. The large monster stands before Ainz, and with one tentacle, lifts him onto the top of its form. Having recounted that, after casting the spell, the Imperial Army was to charge - frightening Nimble as they did not- Ainz is glad they didn't as he wouldn't know what to say to the Emperor had they perished. Instead he decides to do their part and resolve this war. Ainz orders Mare to remain vigilante, but Nimble asks if he is a demon for wanting to continue the killing. Ainz corrects him, stating he is Undead. Turning his gaze, he sees his target.
Back in the Re-Estize encampment, King Ramposa III is urged to leave, but he will not abandon his soldiers. Climb and Brain arrive, finding only an escort team, since everyone else fled in fear. King Ramposa agrees to flee after hearing Gazef is fighting, and he has no further role now in this war. Planning to run one way and a decoy in another, Climb and Brain join the decoy team to best grab the enemy's attention. King Ramposa offers reward to any who return alive; while Climb is content to continue serving Princess Renner, Brain asks if Climb can be allowed to marry Renner, must to his confusion. King Ramposa laughs but confirms he will after ennobling Climb with title; Brain confirms to Climb that he's now has a bigger reason to return alive.
Outside, as troops desperately flee, Gazef stands ready and walking towards the Dark Young. Drawing Razor Edge, he swears to stop the monster from nearing the King's camp. Using "Martial Art: Sense Weakness" Gazef cannot find one, and with "Possibility Sense" he is ready to fight. The monster just merely walks over and ignores him, until he attacks the legs doing no damage and is swatted like a fly. Asking if he is not a worthy opponent, he stops to turn and sees Ainz approach on another Dark Young. Getting a better look, Gazef isn't surprised to learn that Ainz isn't human. As Brain and Climb arrive to aid Gazef, Brain makes note that Ainz is the third person he has seen that is so powerful. Ainz and Gazef exchange pleasant greetings, and Ainz informs Gazef that he has always been undead. Gazef notes Ainz that he did not come here to simply to say hello, and affirming this, Ainz directs that if Gazef were to serve him, he will end the conflict here and now; even snapping his fingers to pause the Dark Young's movements. Gazef refuses, as he owes so much to the King and will not betray him. Ainz tells Gazef that he was willing to die for Carne Village, yet he won't stop the bloodshed. Instead, while owing him a debt of gratitude, the Warrior Captain challenges Ainz in a duel.
- Ainz Ooal Gown uses Iä Shub-Niggurath on the Royal Army.
- The Dark Young begin to massacre the Royal Army.
- The Massacre at Katze Plains occurred.
- Gazef meets Ainz Ooal Gown again in the battlefield.
- Brain and Climb meet Ainz for the first time.
- Gazef challenges Ainz to a duel.
In Order of Appearance
- Jircniv Rune Farlord El-Nix
- Baziwood Peshmel
- Nimble Arc Dale Anoch
- Ainz Ooal Gown
- Mare Bello Fiore
- Marquis Boullope
- Count Lytton
- Margrave Urovana
- Ramposa III
- Marquis Pespea
- Vice Captain
- Gazef Stronoff
- Elias Brandt Dale Raeven
- Boris Axelson
- Göran Dixgard
- Marquis Blumrush
- Brain Unglaus
- No new characters were introduced in this episode.
- Iä Shub-Niggurath
- Reinforce Armor
- Lesser Strength
- Possibility Sense
- Sense Weakness
- There are no new locations shown in this episode.
- In Arwintar, Baziwood and an unnamed scribe discusses with Emperor Jircniv about him requesting Ainz to fight on the frontlines to ascertain the extent of his power.
- Marquis Boullope wonders why there has been no word from Prince Barbro.
- The Great Nobles converse with King Ramposa III at his Royal tent.
- Gazef and Marquis Raeven discussing the strategist he put in charge of the Royal Army is skipped.
- There are no Soul Eaters present on the battlefield, only Death Knights.
- Marquis Boullope orders the left wing to attack when Ainz begins casting his super-tier magic, whereas in the Light Novel he has them to advance before Ainz appears to distinguish himself to Gazef.
- Because of this, Marquis Raeven does not ask Gazef whether he'll accept the "challenge".
- Marquis Boullope is confirmed dead, whereas in the Light Novel, he is only presumed dead due to the left wing he was responsible for being hit by Ainz' super-tier spell.
- Marquis Blumrush is the one who initially orders the Royal Army to hold their ground against the Dark Young and is killed alongside them, whereas in the Light Novel, he was never seen on the battlefield.
- The part where Marquis Raeven desperately tries to flee from a Dark Young and is only spared due to the monster stopping is skipped.