Episode 1: Confidence Recovery
At the Round Table Room, Momonga and Albedo were discussing about the threat of foreign enemies discovering the Great Tomb of Nazarick. While the possibility of being detected cannot be denied, Nazarick's biggest problem is its maintenance costs. Albedo believes that given the situation they should avoid consuming resources as much as possible. Momonga decides to call forth Mare Bello Fiore as he may have an idea on how to prevent Nazarick's discovery.
As a result, the dark elf is summoned to the room. Once he is there, Momonga asks Mare if it possible to hide the dungeon using his magic. In Mare's opinion while to do so would be difficult through magic, it might be possible to cover the walls of the dungeon with earth and grow plants to make it less conspicuous. The idea sounds abhorrent to Albedo as the thought of a piece of glorious Nazarick covered by dirt would be obscene. She is silence by Momonga who asks Mare to continue with his proposal, who then explains that he could make the walls look like hills using [Earth Surge], but as he is now it might be difficult since he lost a lot of his power after he was revived. Mare apologizes for his own inability to relieve the burden of the situation, but Momonga doesn't blame him as they need to try and set priorities and organize the tasks and complete them one by one. Nonetheless, Momonga is a bit more concerned with Mare's lack of confidence in himself.
To change that he decides to handle this right away, putting off the other items on his schedule aside and host a mock combat trial for Mare to undertake. Mare's work with the concealment of Nazrick will be postponed as Momonga believes that he needs to help Mare realize his potential. Albedo obeys the command of her master, promising to make arrangements on the 6th Floor. The elf is thankful that Momonga is doing all this for his sake, but the undead tells Mare that he is like his own child and as a parent he needs to do everything he can to encourage him for the benefit of Nazarick.
Now in the Amphitheater, Albedo states that everything has been prepared. Momonga senses that the Overseer Guardian has a desire to participate in the mock battle so she can regain her own power. Albedo admits that this to be true and asks for forgiveness for being a little selfish, though Momonga does not take offence as it is only natural for her to regain what she lost. Mare arrives and is ready for his mock battle, which Momonga then presents his first challenger, a Nazarick Old Guarder. Afterwards, Mare succeeded in fighting the elite undead, making Momonga consider that perhaps maybe he was worried over nothing after all. The next battle is against a stronger undead than before which Mare defeats.
Momonga tells the elf that was merely a warm-up as the next battle will be up against a Floor Guardian who will be Albedo. He reminds Mare that although this is merely a training session for him, it is meaningless unless he does not take it seriously, but also remember not to intentionally cause injury. A little experiment is called, as he wants both opponents to fight with a handicap and see what kind of results can be obtained. Thus for the time being, Mare is forbidden from trying to make use of area magic in this battle. Not only that, but Albedo is also prohibited from utilizing defense skills as well.
The mock battle between Mare and Albedo commences and the fight showed a close battle with their abilities. Although the match seems even, it was victory for Mare who states that he feels more powerful than when he was fighting the undead. Even Albedo admits that she feels the dark elf's stronger power. Momonga teaches Mare a lesson that if one can properly devise a training method and keep trying, it may be possible to regain his old strength in time. Let alone that, this accumulation of power will surely lead to confidence growing for Mare. Mare understands and thanks his master for his generous efforts.
Momonga asks if Albedo wishes to continue the mock battle further. Albedo believes that she still has some time leftover before resuming her duties in the reconstruction efforts, defense command, and daily work. The two Floor Guardians once again battled, strengthening each other as time allowed.
Episode 2: Sibling Showdown
Momonga sees that the time Albedo spent training with Mare was meaningful for both the two of them. Mare asks if this means that he will be allowed to start working outside from now on? The Overlord wishes for Mare to go out and complete his mission, but there is one more opponent that wishes to test Mare's skills in his training. Mare correctly deduces that it to be none other than his sister, Aura Bella Fiora herself. Aura appears and is eager to get into a battle with her twin brother. Albedo is worried about the duel, as Aura is suppose to be maintaining watch over the Crack on the 6th Floor. The beast tamer assures her the area is secure as she borrowed several undead warriors and placed a double-triple defense wall around the Crack. And due to her skills as both an archer and sniper, she will know right away whether something badly happens in the area. Albedo is still not convinced as she is uncomfortable at leaving just mere skeletons and beasts to man the security of the Crack, feeling that a maid like Yuri Alpha would be required to supervise it. The dark elf feels that she won't be away from the Crack for too long after her battle with Mare, but Albedo decides to supervise the Crack herself, taking Aura's place so that her anxiety won't affect the result of her training which Aura appreciates from the Overseer.
After the Overseer Guardian left, Momonga briefly told Aura about the constraint rule in the mock battle. Aura agrees on it, stating that she will refrain from using her summoned beasts to aid her in the upcoming match. As for Mare, Momonga has forbidden the boy from being able to utilize magic altogether while fighting his twin sister Aura. More so, another measure for both parties to take are that they will also be required to debuff themselves from using magic items too.
Once the two agree to the terms, the two launch attacks at each other at about the same time. While it seemed that Mare had a lot of strength, when he approached his sister, he was caught in Aura's breath. Under her influence, he was defeated by Aura after suffering a severe weakening. Aura looking down at her brother states that he relies too much on magic rather than his physical abilities. Momonga tells Mare the reason for why he lost to Aura was because of how he made the foolish idea to even approach his opponent to get closer while he couldn't use magic. What he lacked was not power, but experience on knowing how to fight in the first place.
The two are asked to fight again, but like the first the second match Mare is the loser, however Aura tells him that he is improving and that he should continue to use moves like feints. Mare is uncertain by that, though Momonga reminds him that this training session is to help build his confidence. Even a strong man does not always win. If Mare can't do it with his own power, he can counter it by using attributes, terrain, or weather. Such ideas come from experience, but what underpins experience is self-confidence which Momonga believes Mare can do. The same thinking can be applied to Nazarick's concealment. He bequeaths him some words of wisdom that "where there is will, there is a way". And not to be afraid to fail as Momonga desires Mare to grow with his own eyes. Mare states that he will meet Momonga's expectations, which the latter is proud to hear from the former.
On the third battle, Mare pushed by Momonga's words, he puts a lot of effort into his hand holding his weapon. And somehow defeat Aura, which Momonga claims to be Mare getting the hang of his confidence and should strive to get used to that sense of achievement. Just before Momonga can dismiss the training session, Aura asks to have one more battle for the last time with Mare, believing he can't make a proper evaluation with a one to one win and loss. Momonga thinks this has to be with Aura trying to recover her pride by defeating Mare this final time around than it being just a simple test. But Momonga agrees that another match may be scheduled at a later date so he can continue with more experiments. For now though, he wishes for the concealment work of the Great Tomb of Nazarick to proceed.
Episode 3: Beginning Concealment
After the mock combat is over, Momonga gently spoke with a nervous Mare about some details in the concealment of Nazarick. Questions like how long it would take for completing that. Mare informs the Overlord that it would take at least around half a day or perhaps a full day to complete Nazarick's concealment. Momonga sees that while the terrain is being changed, they will need to find a way to keep a possible observer from noticing a change in the landscape. He then tells Mare to contact Demiurge and coordinate with him on security. Another question is asked like how many enemies Mare can handle if he is attacked. Mare thinks that if he was at full power he would easily handle it, but in his depowered state he is not so sure anymore. Just to be safe, Momonga provides Mare a Death Knight escort. Not only that but in order to provide Mare some form of communication via [Message], Momonga also has Lupusregina Beta join the concealment mission with the elf.
There is even some worry that if the terrain is changed, that there is a risk of changing the local ecosystem so Momonga asks Mare to be extra careful in dealing with hostile creatures he might end up disturbing while carrying out his task. Momonga suggests to Mare that maybe Albedo should remain on the 6th Floor so that Aura can accompany him on his mission. After some hesitation, Mare accepts the offer, once assured that Albedo would be fine with the arrangement.
With the encouragement of the Supreme One, Mare's feelings are strengthen to conceal Nazarick. Outside the dungeon, Aura surveys the area and tells her brother that she sees nothing out of the ordinary. Mare seeing that it was safe for the time being, begins casting his magic to shift the dirt to cover the walls of the tomb. Both Lupusregina and Aura are impressed by the work he did so far, however the elf warns her friends that something is coming. Mare and Lupusregina who are confused on what she is saying receive a hostile enemy attack when several Forest Worms explode from the earth before them. Lupusregina thinks that the worms are angry because Mare disturbed the soil they were in. Aura tells Mare to continue his work on concealing the tomb as she and Lupsuregina will take care of them.
As Mare concentrates on her work, Aura and Lupusregina meanwhile, with the help of the Death Knight slash through the bodies of the worms. Though outnumbered the group persist, which causes Mare to focus on his work and complete the camouflage of Nazarick with greater passion. Moving the soil of the ground, Mare creates a number of natural valleys and hills to appear around Nazarick.
Episode 4: Unexpected Intruder
Aura and Lupsregina complain about the endless number of enemies that are harassing them. Thankfully, none of the worms have been able to interfere with Mare's work. Lupusregina switches places with Aura and using her magic, floats above the swarm of worms and activates her fire magic, turning them to crisp. Aura apologizes to her brother in her error in judgment at there not being enemies, however Mare is not mad as he believes Aura acted appropriately and that they would continue to work hard so as not to disappoint their master Momonga. The druid uses his magic to alter the area around Nazarick so that it appears as if there is a pond in the valley he formed, and planted flowers on a hill. Just as he was about to form a small mountain, Aura tells him to stop from moving any further than where he is at now as she detects the approach of a human coming near in the area.
From her point of view, she guesses that he is a well-trained person among humans, maybe even an adventurer. Wondering on how they should proceed from here, Aura and Mare tell the Pleaides maid with them to contact Demiurge. In the meantime, Aura advises Mare to put up a fog to hide Nazarick. The maid sends a [Message] to the 7th Floor Guardian who answers. He is likewise surprised that a human managed to slip past Nazarick's security net. The demon states that he has troops on standby, but offers that the group could deal with the intruder themselves if they like to. Both Aura and Lupusregina like the idea as they want to have fun and prevent a human from soiling Mare's hard work. Demiurge asks the ladies that they capture the human alive as he may have some useful information to benefit Nazarick.
Episode 5: Distinguished Service Award
By sunset, the long-term concealment work of the Great Tomb of Nazarick was finally approaching the final stage. Mare now alone surveys his work, reports to Aura via his necklace that it is almost done. Aura in the field at inspecting the hill of flowers, gives Mare some piece of advice to make the landscape more natural looking. As there are a few inconsistencies with his pond and mountain which Mare promises to fix.
Mare soon gets a surprised visit by Momonga who sees that the concealment to be going well. Momonga believes that for Mare's efforts, a reward is in order. The idea of a reward causes a bit of hesitation from Mare since he feels he was simply doing his duty, as a creation of the Supreme Beings. Nonetheless, the undead still insisted that the dark elf should consider receiving something like a reward from him. Momonga then presents Mare a Ring of Ainz Ooal Gown, much to his awe as only the Supreme Beings are allowed to possess one. The Floor Guardian tries to downplay his role, as he feels unworthy of such a gift.
The Overlord though convinces him to accept the ring, reasoning that due to the phenomena of the Cracks, usual teleportation spells do not work within the dungeon. It is an inconvenient issues, as those who are in the position of Floor Guardian should act as commanders of each floor when the enemy attacks. Due to this limitation, it makes getting somewhere fast and escaping difficult, hence the reason why Momonga gives Mare the ring as a reward for his hard-work. So until they can learn why [Transfer Gate] is non-functional, Nazarick would need to use other means to efficiently respond to threats. Mare is just the first of the Floor Guardians that will receive a Ring of Ainz Ooal Gown as the item can allow a user to teleport anywhere a person want in the dungeon. He advises the elf not to lose this special ring as if it fell in to a Chaos Beast's hands, this could be disastrous for Nazarick as a whole.
Finally seeing the merits for possessing such a valuable item, Mare accept the gift from him while promising to continue contributing further to Momonga and his expectations. Aura still on the magical via asks why Mare stopped working on the landscape. After Mare informs her of Momonga's presence, Aura responds that she will be over at his position soon. As Momonga waits to see Aura, he comments on the impressive scene Mare was able to construct with the power of his druid magic. The other dark elf twin arrives, who sincerely apologizes for being late. Momonga tells her not to worry about it, but promises that he intends to give her a reward at a later date for her work. Aura though believes credit should be given to Demiurge as it was his plan to begin with that helped captured the human intruder. Still, Momonga wants to repay her regardless for supporting the plan. Before she can accept, Aura notices Mare's left hand and the Ring of Ainz Ooal Gown on it. Mare asks her what's wrong? In response to that, Aura demands to know why Mare placed his ring on a particular finger.
- This character scenario was released alongside the Memory of Chaos: Sebas Tian, Memory of Chaos: Pandora's Actor, Memory of Chaos: Aura Bella Fiora, Memory of Chaos: Cocytus, Memory of Chaos: Demiurge, Memory of Chaos: Shalltear Bloodfallen, Memory of Chaos: Albedo, and Memory of Chaos: Momonga.