Heteromorph Night Parade

Heteromorph Night Parade (異形夜行譚) is a game event in Mass for the Dead that was released on August 15, 2020 to September 5, 2020. The event was re-released on August 6, 2021 to August 16, 2021. And again on August 16, 2022 to August 31, 2022. And later on August 1, 2023 to August 15, 2023.

Background
An invisible presence causes Hamsuke to be frightened, even though there is no sign. Momonga, who was associated with the supernatural report to "ghosts," reassured his frightened subordinates and ordered Aura to search and capture this mysterious existence in order to grasp its identity--

Incident
Hamsuke fidgets at the sound of a rustle in the bushes. It turns out to be Aura Bella Fiora who greets her pet. Noticing her subordinate's fear, she asks what's wrong. Not only is the Wise King of the Forest unease but the goblins and Death Knight are visibly frightened by something. Aura thinks that maybe they were attacked by an enemy, but Hamsuke testifies that isn't the case. Just the other day at midnight, Hamsuke was patrolling her territory as usual, when she encountered a big shadowy figure. When it tried to approach her the beast's instinct was to flee. The other forest denizens admit they also have seen it, and sense that something in the trees was watching them at night. Strangely they never exactly saw what it was and there were no traces of anything in the area.

Aura seeing this to be indeed strange, then goes to Momonga. The Overlord after hearing the report, is wary as Hamsuke who is a powerful creature in her own right, was easily scared by this new presence. The fear effect sounds similar to [Aura of Despair], leading to Momonga to wonder if Hamsuke and her goblins may have encountered a ghost. Aura believes that it to be a plausible theory as an astral monster could go intangible and escape detection through the forest. While Momonga finds it fascinating that there may be native spirits in the New World, given his report on a Ghost Ship, it brings an intriguing thought on life and death in this new realm.

However, he focuses on the task at dealing with this "ghost" lurking in the Great Forest of Tob. So far it seems content to be watching Hamsuke and the others from the shadows, but Nazarick cannot just let this continue. Feeling it to be upper management's duty to ensure the safety and morale of their subordinates, Aura is given permission to lead an investigation team and possibly capture the entity.

Back in the Tob Forest, Hamsuke and her goblins are welcomed to the sight of Aura returning with Narberal Gamma, Slimeko and the protagonist. Glad they are here to help deal with the problem, Hamsuke listens to Aura's theory that they may be dealing with a "ghost." While the monster had never encountered a ghost, her goblin subordinates have heard second hand accounts from humans that ghosts roam the forest. She believes that Aura may be correct. Aura inquires if the goblins have heard of any specific method to kill ghosts, sadly they do not admitting they heard it from humans clustered around a fire, apparently telling a ghost story. Narberal thinks that they may be overacting, as the entity could still just be a weakling. Hamsuke insists what she saw was dangerous. Aura then speaks telling everyone that it was still too early to tell and more testimonies are needed. As she speaks, she briefly senses a presence behind her. Turning around there appears to be nothing, drawing questions from her companions on what distracted her. Aura brushes it off claiming that it was just rustling leaves and motions to find more witnesses.

The next testimony to have seen the entity is an ogre guard from a nearby goblin colony. The ogre admits to the investigators from Nazarick that he saw a shadow while he was on duty, but strangely he describes it to be small, different from Hamsuke's account. It was pondered that the ogre and Hamsuke's height differences are to blame on their perceptions, but when the ogre gives them the shadow's approximate height, validating that the entity was way smaller than both witnesses. The group believe perhaps what the ogre saw may have been something completely different. In the worse case it hints that not just one mysterious entity is now roaming the forest. Still it's too early to draw conclusions and then the party go to the next witness, the Death Knight.

From the undead's testimony is swore that it saw a floating fireball in the forest. The phenomena obviously frightened it. When questioned on whether it may have been a Chaos Beast from the Crack, the undead told the Floor Guardian that the fireball appeared in the opposite direction. Narberal still remains skeptical of the account, thinking that the Death Knight may have mistook a glowing torch for a ghost due to its poor vision. In the Death Knight's defense it wanted to get a closer look at the entity but when it tried to approach the fireball, the thing vanished in smoke. Aura admits that there is something strange going around in the area after listening to the testimonies, that and her uncanny feeling that something is watching her.

After several hours the group reach the north side of the Tob Forest in the area near the Great Lake. Hamsuke wonders why they traveled here if they are suppose to be looking for more witnesses on the mysterious entity. Aura tells her pet that they came to meet someone to help them. Suddenly a hydra appears and lumbers toward them, causing Hamsuke to go on the defensive. Aura calms her down and introduces Hamsuke to Rororo, the pet of Zaryusu Shasha. The lizardman traveler from Green Claw soon arrives and greets his friends. Once he is introduced to Narberal, he asks why the protagonist and his company called him out to help guide them. Once he learns of the strange occurrences in the forest he understand the situation, he thinks maybe someone in his village may have seen something. Hamsuke is asks to remain behind so as to not frighten the other lizardmen. To keep her company, Zaryusu asks Hamsuke to spar with Rororo. The two immediately hit it off, wrapping their tails on each other's neck in a handshake after their owners depart.

At Green Claw village, none of the lizardmen have seen any strange, given they do not venture that far into the forest. Having no new clues, Narberal suggest perhaps that they have narrowed the mysterious entity's haunts, but Zaryusu interjects believing that the new entity could be a new monster species. He points out that ever since the incident concerning the Cracks, the territories of the inhabitants of the forest have been fluctuating. This newcomer could be something that migrated recently. The traveler states that his tribe have recently ignored the impressive monsters that have come their way seeing it mundane, but there is one individual who can help them. He takes them to his older brother hut, Shasuryu Shasha the leader of Green Claw. The chieftain is also hosting another guest, Kyuku Zuzu, the chieftain of Razor Tail. Ever since Zaryusu's meeting with the protagonist and his friends on their last adventure, the traveler having been inspired by their words of unity, managed to convince his brother Shasuryu to establish more permanent alliances with the other tribes given the state of the world. The two chieftains greet the party, though Zaryusu wishes to speak with Kyuku for his knowledge. Though being the bearer of the White Dragon Bone sacrifices much of his wisdom, the chieftain still retains enough to aid the investigators. Given what they described to him about this unseen entity, he believes it to be the work of the Demon Snake of the West, one Three Monsters which include the Giant of the East and Wise King of the Forest.

Aura wishing to get more information on this trio, tells Narberal to use [Message] to contact Hamsuke outside the village. Unfortunately the hamster is clueless on the monsters. Aura manages to piece what they learn so far from Kyuku as it seems that in the past the three monsters maintained a tenuous balance in the forest. None dared to invade or attack each other since the other was afraid that the third member would retaliated and attack their territory. However ever since the incident with the Cracks, the power balance must have been broken, as Hamsuke had fled from her territory after being driven away by the Chaos Beasts and Contaminated Beasts. Hamsuke may not have only been affected the other monsters: the Demon Snake of the West and Giant of the East may have either fought each other or were likewise driven into hiding by the creatures from the Crack. However since Aura took Hamsuke under her wing as her pet, it could mean that the other two monsters may be trying to subvert or take control of the southern forest. Kyuku states that the Giant of the East is actually a troll, and thus does not match with the ghostly entity that has been stalking people in the forest. The other being the Demon Snake of the West though has the power of invisibility and seems to be the likely suspect. The chieftain knows where the residence of the Demon Snake of the West, though is unsure if the monster still remains there. To assist, he decides to join the investigation. Zaryusu accepts the aid, telling his older brother that the whatever is happening in the forest could affect the lizardmen, and the chieftain of Green Claw agrees to make preparations to inform the other villagers of the danger.

Aura warns the group that the Demon Snake of the West could still be unrelated with the "ghost" in the forest. However to be sure, Aura decides to split the group into three. She has the protagonist, Narberal, and Slimeko head to E-Rantel to learn more information on the ghost story the goblins heard from those passing adventurers. To aid them in a fast trip she offers a flying beast to get them to the city. Next, she plans to have Hamsuke return to the forest and guard her territory with the Death Knight. Meanwhile she, Zaryusu and Kyuku search for the Demon Snake of the West.

Both Aura and Zaryusu travel to the lair of the Demon Snake of the West, with Kyuku as their guide. Due to his fading memory, the chieftain has trouble remembering the exact path. What little he does remember of the Demon Snake of the West is that it is a powerful foe. Aura heeds his caution, before the group run into a trio of slimes forcing them to fight. In E-Rantel, the protagonist and his friends make their way to the Adventurer's Guild in hopes of finding more information on the story the goblins heard. So far none of the adventurers they talk to have ever heard of rumors ghosts in the forest. One even tries to make a pass at Narberal, which earned him a kick in the crotch. It becomes clear that the adventurers who traverse into the Tob Forest never go beyond the periphery when collecting herbs. However the trio are soon reunited with four familiar adventurers in the lobby.

Back with Aura and the lizardmen, they finally reached the supposed lair of the Demon Snake of the West, a dark cave that appears to be empty. Aura taking a closer look spots a bunch of goblins hiding in the shadows. When they are exposed, the goblins reveal themselves. Before Zaryusu could try to negotiate with them, one of the demi-humans attack, throwing a stone at Aura. The stone is deflected by Aura's skill countermeasure that blocks projectiles. Aura knows that the goblins are actually the minions of the Demon Snake of the West, who she sees to be invisible, and calls out to them and their master that she only wishes to talk. When the goblins refuse to back down and meet her with violence, Aura then demonstrates her power and kills them in a flash. Directing her attention to an empty spot in the cave she coaxes, with a bow and arrow, the Demon Snake of the West out to dispel his invisibility. Now finally revealing itself to be a naga. The naga pleads to be spared its life. Aura states that she merely wants to talk, though the naga believes that to be a lie, until he is convinced otherwise by the threat of Aura's weapon. Aura then asks the naga to tell her everything it knows about ghosts.

From the naga the dark elf and lizardmen learn that one of the former's minions had observed a large shadow in the vicinity of the abandoned Carne Village on the south side of the forest. The naga explains that ever since the Crack appeared in the forest, he has been searching for a new safe haven. As for the shadow near the village, he assumed it to be the Wise King of the Forest. Aura hearing enough tells the naga that the big shadow is the Wise King, and that it has become her pet, much to his shock. She refrains from informing the naga of Hamsuke being frightened of a ghost less it lowers the latter's image. Before she leaves, Aura places one of her pet wolves with the Demon Snake to ensure that he sends her any new information he might discover. Aura is then guided back to the edge of the forest by the lizardmen, but before she could say her goodbyes, a peryton lands reporting to Aura that the "ghost" appeared again.

The Death Knight and Hamsuke are busy battling a wave of Chaos Beasts emerging from the Crack. While her undead partner is occupied in killing the monsters, Hamsuke panics when she sees the giant shadow coming from behind. She tells it to stay away. The timely appearance of Aura landing out of the sky interrupts the hamster's fear and she aids her subordinates in cleaning up the area. Once all the Chaos Beasts have been killed, Hamsuke tries to direct her master to where she saw the "ghost", but the spot where it was is empty. Hamsuke is sure that something was there, Aura does not deny her pet's claims as she vaguely senses that something is in the trees and is currently watching them. Suddenly a thick fog covers the area, and Aura struck by something. A silhouette of a great shadow is seen in the haze. Feeling the bow from the entity, Aura wonders if its really a ghost. But she put those thoughts aside as she, Hamsuke and the Death Knight engage this new threat.

Aura swiftly dodges the thing's attacks when to her surprise it speaks and demands that they leave. After landing a blow on the entity, it scares it away back into the forest, lifting the fog. Hamsuke wonders if they should give chase, but Aura orders her pet to remain, as they do not have the resources currently to capture it. Now that she has an idea what it is, she decides to return to Nazarick and orders Hamsuke and the Death Knight to head to the goblin colony in the meantime.

Aura and the protagonist are back in the Nazarick and give their reports to Momonga. It becomes clear that whatever Aura faced is an unknown entity but what is for sure it is not a spirit. Aura thinks it to be some sort of demon beast based on her Beast Tamer intuition. Aura wishes to plan a capture for the beast, though Momonga wonders if there should risk it as the opponent seems powerful. Aura is confident that she can trap in with the right plan. Momonga then asks how they could lure it to them, which the protagonist happily answers.

Earlier when he and his team were in E-Rantel, the four adventurers they met in the Adventurer's Guild turned out to be the Swords of Darkness. The two groups were eager to see each other, save for Narberal who had completely forgotten the adventurers. After hearing that the protagonist was looking into a stories about a ghost roaming the Tob Forest, the adventurers were able to clear some of the details.

The "ghost" actually stems from local folklore of Carne Village. It was said that an evil curse was placed upon the land at one point. In an old story from the former villagers of the Carne Village, the Harvest Festival was said to entertain and calm evil spirits who got angry and caused poor harvests. Traditionally a Harvest Festival is held every year. It seems that whenever a harvest festival was stopped, the crops would wither for a strange reason. To prevent unsuccessful harvest, the chieftain had to reinstate the festival as it was believed to prevent such disasters. Strange as it may be, it seems that ever since the villagers evacuated from Carne Village due to the Chaos Beasts, no Harvest Festival took place, hence explaining the strange presence in the forest. Seeing this festival as a means to lure the creature them and capture it, Momonga commands his subjects to organize their own Harvest Festival for the trap.

The next day after procuring the necessary materials for the Harvest Festival, Aura brought over a team to Carne Village to prepare the festivities to lure the beast. Assisting her in the plan were her brother Mare Bello Fiore, Slimeko, the protagonist, the Death Knight, the Pleiades, goblins and several Skeleton summons. After cleaning what the could of the village plaza, the group established an crafted altar provided by Demiurge and dressed the area in lanterns, to recreate the festival based on their research from the survivors of the village. However the protagonist added some creative additions such as allowing the Pleiades to wear yukatas attire normal used during a Bon Festival though the festivities are similar to allow for such use. When night falls and the lanterns are lighted the heteromorphic festival then begins and the gathered then walk around the alter and dance. While the festival is for a trap, some of the members take certain joy in the celebration.

One of Aura's wolves reports that several Skeletons are approaching the villager. Seeing as the undead came from the outskirts of the village, the party-goers speculate that the undead have naturally spawned due to the skeleton summons and Death Knight. As the festival is a day to memorialize the dead, the group then decide to clean up the interlopers before resuming the festival.

The undead having been defeated, Aura asks Lupusregina Beta if she has seen anything, which the maid answers yes and strike a seemingly empty space, only for something to yell in pain. A dense fog rolls in, indicating that their target is in the area. Aura calls out to the entity that her ability to use [Perfect Unknowable] is useless against Lupusregina as she can see through it naturally. Its cover blown, the beast then appears before everyone, revealing it to be an giant golden nine-tailed fox who calls itself Kyuko and demands they leave before launching a [Fireball] at them. Its ability confirms it to be the same entity that the Death Knight saw in the forest, though Aura still ponders on the small shadow that the ogre guard had seen and worries if there is still another. The fox attacks the group, easily dodging Aura's arrows despite its size. Mare lends his power and encloses the fox in [Earth Surge] so Aura can launch arrows at the trapped beast. The fox laughs at the attempts to imprison it and bursts right through to avoid the volley, but finds the Pleiades waiting for her in an ambush. It continues to dodge the maids attacks, so Narberal takes to the sky to cast Twin Maximize Magic [Chain Dragon Lightning], however the spell proves useless as it is blocked by the creature's magical barrier. The only one to land a hit is CZ2128 Delta who uses her weapon to strike it. To the surprise of the attacker, the beast cries out in a girl's voice and then the fog dissipates.

There before the agents from Nazarick the giant fox transforms into a little girl with nine tails. Shizu is nearly driven crazy at seeing the adorable girl, before she is brought to her senses by her comrades. Despite being small. Kyuko continues to battle Aura and her allies displaying her full magical abilities shooting a barrage of fireballs at them. Seeing that their opponent favors long distance attacks, Shizu then counterattacks by firing her weapon at the fox, frightening her. Aura attempts to ask the fox to halt her attacks and talk through discourse by the fox girl launches [Fire Fox] instead. At the end Kyuko soon finds herself in a one on one duel against Aura. At opposite ends of the field, they charge at each other with attacks. Once they end their pass, Kyuko falls in defeat. Being defeat, Kyuko ask to be given on request, to free 'her'. Aura is confused at who she is referring to until she sees that the fox is talking about Hamsuke. It appears that Kyuko is under the impression that Hamsuke is tormented by Aura and Narberal. While the latter is partially true, Hamsuke tells the girl that she is not being mistreated and that Aura is in fact her master. Kyukistune is further confused as she still believes Aura and her friends are evil people, pointing out the bizarre ritual dance they complete and the gathering of undead. When they informed her that they were just having a festival and the undead were circumstantial, the fox wonders if her long journey may have affected her judgement. Learning that the fox is not native to the area, and hence not the evil spirits the Harvest Festival was meant to appease, Aura asks Kyuko to tell her story from the beginning.

Kyuko explains that she came from a distant land, where she was once a normal fox but through certain circumstances became a nine-tailed fox able to transform. She made her way to a nearby human village where she was worshiped as a god. Eventually all the villagers had passed away, leaving her alone. Longing for companionship, Kyuko went on a journey to find others of her kind. However years passed and she continued to wander without ever meeting another one like her. The fox eventually made her way to the Great Forest of Tob, where she saw Hamsuke, who she believed was a similar existence to her as they were both unique monsters. The times she approached the hamster were attempts to a speak with her but unfortunately her beast form caused Hamsuke to be scared away. And later when she was at the Crack, she was attempting to help and protect Hamsuke from the Chaos Beasts. While she was watching Hamsuke interact with Aura and her companions she could help but see that Narberal verbal scorned Hamsuke thus explaining her actions against the group as a whole. The whole incident seem to be a bad case of misunderstandings. Kyuko admits that the events that happened are her fault due to her poor social skills. Hamsuke having heard of Kyuko's lonely life asks Aura to not punish the fox. Despite being a victim in this incident, Hamsuke understand the feelings of Kyuko as she was the only one of her kind. Aura seeing that no permanent harm has been done, decides to let bygones be bygones though she extends an invitation for Kyuko to join her group. Hamsuke gladly supports the idea believing that she and Kyuko will be good friends.

This all befuddles Kyuko as they readily accept her despite all the trouble she caused. The others though in their eyes see cannot feel anger at Kyuko as they see just a lonely child. To give Kyuko a proper welcome in joining Nazarick, the Floor Guadians decides hold the Harvest Festival in her honor. After refurnishing the decorations damaged during the fight, the festival recommences. Kyuko finds herself being lifted on Hamsuke who begins to dance in the plaza. Shizu also dots over the fox girl even planting a One-Yen Sticker on the her back to signify she likes her. As the other Pleiades watch the fox girl happy and at play, Yuri cannot get rid of a nagging feeling that Kyuko seems familiar. It soon dawns on her why, and she approaches Kyuko if she would still like to meet another of her kind as fate would have it one of her sister's subordinates resembles Kyuko. When she mentions the being's name as Uka-no-Mitama there is a flash of recognition in the young girl.

Aftermath
In the end, Aura reports back to Momonga declaring that she successfully caught the entity causing the ghost haunting, Kyuko and convinced her to join the Great Tomb of Nazarick. While Kyuko's power was moderate in comparison to the beings in the dungeon, Momonga still finds her addition into their ranks to be significant. He is more intrigued in Kyuko's country of origin, which most likely hold clues that a player from YGGDRASIL helped develop its culture. From the information it seems Kyuko's homeland is a place where Japanese culture has taken root. All evidence points this to be true, from the girl's clothing to even her knowledge of Uka-no-Mitama, a monster whose description was passed down traditionally.

Aura returns to the Tob Forest, where she encounters Kyuko chasing a tired Hamsuke in play. She notices that Kyuko is now wearing a fox mask, which turns out to have been given to her by Uka-no-Mitama. Kyuko looks more at peace and innocent, compared to her somber attitude when the elf first met her as she enjoys her new role as a member of Nazarick.

After a while, rumors began to circulate among the refugees from Carne Village that the devastated village had been restored and that the occurring undead had vanished. Most of those who heard these rumors believed that some former members of the village had returned to take care of the area. Others though speak of a new guardian of the land existing in the area of Carne Village. There is even a witness who claims to have seen this guardian, describing her be a young girl with a fox mask.