Zenberu Gugu orders his tribe that he will duel Zaryusu Shasha. Should the latter win, he would be Dragon Tusk's new chieftain. Zenberu is eager to fight against Zaryusu seeing him as a top grade warrior. Zaryusu agrees on the condition that Crusch Lulu be spared should he fall. As the duel between the two progresses over time, Zenberu manages to land a blow on Zaryusu, but he eventually loses due to exhaustion from one of Frost Pain's abilities. After the match, Zenberu later hosts a feast for the two. At the feast, Zenberu pledges to have his tribe join the war against the Supreme One, but asks if they can win. Zaryusu doesn't know, yet feels as if the enemy possesses overwhelming strength were arrogant enough to deliver the warnings to the tribes. Zaryusu plans to exploit that arrogance when their forces clash, though Crusch believes its better to surrender and risk enslavement. The former counters that if they choose enslavement they may risk losing much more, but Crusch believes it to be the best course. Despite their different views, Crusch ask Zaryusu not to die, to which he complies, not until she gave him her 'answer'.
Four days before the undead invasion, the trio then arrive at the village of Razor Tail, where the other remaining tribes have gathered. At the chieftain meeting, the chiefs decide to create a small elite unit composed of the chieftains. To compensate for the lack of leadership in the field, they designate the Head Warriors of each tribe to be the commanders.
Cocytus orders his army to advance, whilst Ainz Ooal Gown has been informed of the development. Back at the Great Lake, the undead army composed of skeletons, zombie beasts, etc. march to attack Razor Tail's Village. Shasuryu Shasha, tells the gathered lizardmen not to waver and attack. The two armies engage, and thanks to the lizardmen's morale and preparation they are gaining the upper hand. Cocytus, seeing that he has underestimated his opponents, calls Demiurge for advice so as not to disgrace Ainz Ooal Gown. Demurige instead asks Cocytus to think of the various disadvantages that Ainz Ooal Gown set him up with in leading this army. He proposes that perhaps winning is not the goal of Ainz, but instead reminds him that Ainz wishes to test Cocytus in thinking for himself. Before he could elaborate further, Demiurge apologizes and cuts the call.
Faced with little options, Cocytus deploys Iguva=41. The elder lich easily dispatches the Head Warriors, causing the lizardmen in the battlefield to withdraw. The chieftains, seeing this obstacle from afar, deduce Iguva=41 to be the commander. Using Rororo as a shield, Zaryusu, Zenberu, and Crusch engage the undead close enough for them to attack him. The elder lich summons Skeleton Warriors to combat his opponents. While Zenberu fought against the skeletons, Zaryusu and Crusch face off against Iguva=41. After freeing Zaryusu from Iguva=41's fear spell, Crusch was attacked by the furious lich. Zaryusu engages the lich one on one. Unwilling to use Frost Pain's area effect ability, as his comrades were too close, Zaryusu instead creates a mist around him. Iguva=41, unable to see him, lowers his guard allowing the lizardman to stab him in the skull. Iguva=41 attempts to choke Zaryusu, but succumbs to his wound. The death of Iguva=41 signals the undead army's defeat and a victory for the lizardmen. Cocytus looks on in disbelief but also admiration of the display. Entoma then informs him that Ainz wishes to speak to him.
- Zenberu and Zaryusu duel, ending in Zaryusu's victory.
- The lizardmen tribes unite to become the Lizardmen Alliance.
- The undead army of Nazarick and the Lizardmen Alliance face off.
- The Lizardmen Alliance defeat the undead army.
- Nazarick had suffered its first loss.
In Order of Appearance
- Zenberu Gugu
- Zaryusu Shasha
- Crusch Lulu
- Shasuryu Shasha
- Entoma Vasilissa Zeta
- Narberal Gamma
- Ainz Ooal Gown
- Head Warrior of Green Claw
- Head Priestess of Green Claw
- Natural Steel Weapon
- Steel Skin
- Resistance Massive
- Middle Cure Wound
- Icy Burst
- Summon 4th tier Undead
- Lion's Heart
- Magic Arrow
- Negative Touch
- Razor Tail Village
- Ainz receiving a message from Albedo about Cocytus and the upcoming war with the Lizardmen.
- The ritual uniting the lizardmen tribes in the Light Novel was not included in this episode.
- Crusch did not use "Middle Cure Wound" multiple times to support Zaryusu in his fight against Iguva=41 as much as she did in the Light Novel.
- Zaryusu did not let go of Frost Pain upon landing a hit on Iguva=41 with it. Instead, he would continue using Frost Pain to slash at Iguva=41 in his weakened state.
- The Blood Meat Hulks did not make their appearance, when they were supposed to guard Iguva=41. Instead, it just jumped straight to Iguva=41 who is firing fireballs.
- Since Snap Grasp did not make its appearance in the anime, Zenberu had to fight all the Skeleton Warriors by himself without any help from the summoned monster.