Nazarick Revitalization Plan -Start- (ナザリック再生計画-始 動-) is a game event in Mass for the Dead that was released on March 1, 2019 to March 11, 2019. The event was re-released on September 1, 2020 to September 15, 2020.
Suzuki Satoru reflects how he used to be a player for the DMMO-RPG, YGGDRASIL. However, at the moment of the shutdown of the game, he finds himself in a different world along with the Great Tomb of Nazarick he and his friends created. Now under his name "Momonga" and as the last member of Ainz Ooal Gown, he struggles to make sense of his new situation.
In the Round Table Room, Momonga along with Albedo assesses the damage caused to the dungeon after they were transported from YGGDRASIL. The Overseer Guardians reports that the damage is significant, but thankfully the Treasury is undamaged as well as its contents. However the cost of restoring the dungeon and resurrecting the deceased NPCs may exceed their expectations. Another problem is that even if they choose to revive all the Floor Guardians, they may be too weak and possibly die a second time. So far they managed to resurrect NPCs with the minor costs but that will still not be sufficient in defending the dungeon in emergencies. Demiurge who has been recently revived joins the meeting and adds his input. His main concern are the Chaos Beasts that now plague Nazarick from the Crack in the Throne Room. While they have placed summons to guard the area it is still an ongoing threat. The demon questions if the phenomena is a natural occurrence or perhaps some kind of attack from beyond. The threat the Crack and Chaos Beasts pose will undoubtedly hinder Nazarick's reconstruction efforts. Albedo agrees with her colleagues assessment given that this enemy's foothold is within their base, she believes that perhaps it would warrant to build a new base outside of the dungeon for safety.
Momonga hearing this, finds it to be unacceptable as it would mean abandoning Nazarick. Albedo tries to console her master stating the move would be temporary and a preparation for the worst to protect Momonga. Demiurge, however, doubts that the outside world will be any safer than in Nazarick and that the safer route would be to prioritize Nazarick's reconstruction.
Albedo is a bit dissatisfied at being outvoted, but Momonga assures her that her idea was sound. Demiurge proposes that they do a survey of the Crack as its nature is currently unknown. Since it is too dangerous to approach carelessly they will need to send their low-ranking members to confirm the danger before shifting to a full-scale investigation. They decide to send in their human type members to access the situation, for which Albedo then recommends members of the Pleiades. Momonga permits this and allows the plan to move forward ending the meeting.
Later Momonga is seen in an audience with Yuri Alpha and CZ2128 Delta who have been selected for this survey mission. Despite the unknown risks the maids agreed to take the assignment. To prepare them for the upcoming survey Momonga decides to hold a mock battle for the maids which he believes will help regain some of their lost job levels. Taking this to his office, he summons a zombie beast and has it fight against the maids. After battling it, Yuri and Shizu comment that their powers have slightly restored. Momonga decides that they are making progress continues his experiment and intensifies the training.
While Yuri and Shizu train at Momonga's instruction they are watched by Lupusregina Beta. Solution noticing her sister's interest asks if the other maid had completed her duties. Lupusregina confirms that she has and was merely observing, a bit jealous of the other two maids' personal attention from Momonga and serving him directly. Momonga suddenly appears near them causing Lupusregina to panic and apologize for slacking off. The Overlord is not seeking censure but is inviting the two to train with Yuri and Shizu in a mock battle to hopefully improve their abilities. The two accept, excited to be of use to their master.
Momonga has the battle maids spar with each other, with Yuri fighting with Lupusregina, while Shizu fights Solution. Momonga is saddened to see his friends' children fight, but understands that it is necessary. To act as a guard while the Pleiades train, Momonga summons a Death Knight. He then resumes watching the four women combat each in their mock duels. The maids battle their hardest in earnest for the sake of impressing Momonga. A [Message] is received by Momonga from Albedo urgently reporting that the Crack in the Throne Room is being flooded with Chaos Beasts. Demiurge is currently with the undead summons but Momonga's assistance is requested. Yuri noticing the exchange requests that she and Shizu be allowed to join. The Overlord permits them to join but reminds them to refrain from careless behavior.
At the Lemegeton the forces of Nazarick are finally managing to eliminate the Chaos Beasts that are flowing from the Throne Room. Now that they have breathing room, Demiurge reports to Momonga that the Chaos Beasts are constantly appearing and moving from the Crack located where the Throne of Kings once stood. So far the undead in the room are attempting to maintain the line but if this keeps up, they will be overwhelmed. Momonga though capable of creating undead via summoning will only last temporarily. If he had corpses, permanent summons would be possible though no corpses are available for his use. Faced with the choice of depleting the funds from the Treasury, Momonga believes that he should handle the Crack himself. Demiurge strongly advises against that option as now the Crack is emitting some strange black fog along with the Chaos Beasts. Though they cannot confirm that the black fog can cause abnormalities the Floor Guardian believes they should be cautious until they can confirm. More Chaos Beasts interrupt their discussion forcing the defenders to direct their attention.
Yuri and Shizu fight the hardest, furious at these things trespassing on Nazarick's sacred soil. Soon Demiurge receives a report from a Shadow Demon reporting that the undead contingent in the Throne Room is being pushed. Momonga suggests using his skil [Undead Lieutenant] to summon more allies to hold the line, but Demiurge states that the Chaos Beasts are too strong and that they should prioritize his safety. Yuri and Shizu volunteer to be sent to the front lines as they are the most optimal forces in Nazarick so far, expressing their desire to protect their home and sisters. Albedo supports the idea stating that the maids will most likely be able to handle whatever situation they find behind the doors to the Throne Room. Momonga, feeling the pressure, consents and orders the maids to advance while he and the others work to clean up the Chaos Beasts in the Lemegeton.
In the Throne Room, Yuri and Shizu are faced with the hordes of Chaos Beasts that have flooded the chamber. The two combat the invaders, Yuri launching a barrage of punches while being supported by Shizu's Magic Gun. Yuri finds the experience exhilarating as they now are doing what they were created for.
Back in the Lemegeton, thanks to the maids cutting off the flow of Chaos Beasts, the defenders there are having an easier time. However, immediately when Momonga and the group begin to be relieved they feel a low booming sound in the earth coming from the Throne Room. A Giant Chaos Beast emerged from the Crack and is faced by Yuri and Shizu. Soon the two maids are fighting a fierce battle with the giant. Together combining both their attacks the two manage to slow the beast down and cut its health until it falls. Its death is coincided with the black fog that was leaking from the Crack ceasing and fading away.
In the Round Table Room, Demiurge reports that the black fog and Chaos Beast activity has disappeared. While they cannot confirm that they will be attacked in the future it shows that the Chaos Beasts forces are not infinite. Momonga personally thanks the battle maids Yuri and Shizu for their assistance in this incident and tells them to rest. Once they are gone from the chamber, Albedo reports that now that they've learned that the Cracks times for spewing Chaos Beasts are limited, that perhaps they will be able to resume reconstruction efforts starting with the Lemegeton and restore the final defense. However Momonga believes that a new defense system may be required, a mobile defense unit to supplement the current passive one in order to secure the dungeon. Albedo agrees with the idea and Demiurge believes that with this they may be able to restore the other Floor Guardians sooner than expected. In the spirit of these plans to strengthen Nazarick, Momonga decides to christen this as the Nazarick Revitalization Plan.
On the 6th Floor, Yuri and Shizu are cleaning up a bunch of Chaos Beasts. They are soon joined by Lupusregina and Solution seeking to have another spar which Yuri accepts as a challenge. Meanwhile, in the Amphitheater, Demiurge is contemplating on his thoughts. He is approached by his subordinate who asks if there is anything wrong. The Floor Guardians has been thinking on the nature of the Cracks and questions why the shapes of the Cracks on the 6th and 10th Floor are almost standard and identical. He ponders if perhaps there are some sort of rules that they work under, reasoning that one of the abilities of intelligent lifeforms is to recognize patterns. Through the Cracks, Demiurge thinks that he sees something disturbing and that the Cracks were possibly left by something or someone. The subordinate is apprehensive of the thought of such a powerful existence that can create such phenomena within the dungeon. Demiurge though assures his minion that this was all speculation and that it is unconfirmed. However as the Floor Guardian is left alone, Demiurge still wonders on the identity of the mastermind behind the Cracks.