"Ambition in the Demon Army" (帝鬼軍のヤボウ Teiki Gun no Yabou?) is the third episode of Seraph of the End: Battle in Nagoya, fifteenth episode of the first season, and fifteenth episode overall of the Seraph of the End anime.
A young boy sends a letter via messenger pigeon to Aoi Sangu, who passes it on to Kureto. Shinoa Squad meets, and Kureto Hiragi and Guren Ichinose do the same. Kureto announces his plan to attack and wipe out ten noble vampires in Nagoya before the vampires bring their main army down on Japan in one month.
Shinoa reveals that Yu tried to kill her during the battle in Shinjuku, and the squad considers whether to keep following Guren or not. Eventually, they decided to follow him and make their policy to protect their family.
Shinoa briefs Guren on her squad's success in training, and he gives her new orders. Mika meets with other vampires to head to Nagoya, and Kureto orders potentially lethal experimentation on Mirai Kimizuki.
The child who contacted Ferid Bathory previously is seen wandering the passages and walkways of Sanguinem. He encloses a note in a scroll case and attaches it to a carrier pigeon which he sends to fly out through a broken pipe. The pigeon makes its way across the ruined city where by daytime Aoi Sangū receives the intelligence. In the headquarters, Kureto Hīragi reads the note and simply orders her to bring Guren to him.
Elsewhere, Yu is making attempts to stop his hair from sticking up, and he, Kimizuki and Yoichi go to meet Shinoa and Mitsuba for breakfast and to discuss about the recent events. They run towards a scream from the kitchen to find both girls grapple over a flaming pan. Kimizuki demonstrates his cooking skills by making omelets. Yu, suspicious that he is being left out of something, breaks the ice and Shinoa responds that there are two things to discuss. The first is that Yu may have been the object of human experimentation, and he lost control in the heat of battle and tried to kill Shinoa, much to his surprise.
The second issue is that Shinoa is unsure whether or not Guren is truly on their side. Yu protests that Guren has been the one looking out for them the whole time but Shinoa suspects the possibility that he may have in fact been using them this whole time, specifically Yu. Mitsuba believes that Guren may view them as assets to intimidate his superiors but also considers that something bigger then that may be at stake. Kimizuki feels the same as Yu, it’s all new information for him. Squad leader Shinoa thinks that they need to make the decision on whether they are to stick by Guren, weighing the possibility that he’s behind them against the chance he is manipulating them. Shinoa considers that they may be considered traitors to the army if they end up following Guren and it transpires that he is using them as weapons, even if they are just following orders.
Guren himself answers Kureto’s summons in an enclosed encampment on the roof of a building in Shinjuku, where three vampires were kept chained to a black scythe. Guren deems it disgusting that starving vampires are kept as captives as he turns to face Kureto sat above monitoring him. Kureto confirms Guren’s question as to whether this is a cursed gear experiment, namely to turn vampires into demons and harness these powers. Guren confirms that he came alone, unconcerned with the possibility that Kureto could have had him killed since he is of use to him. Kureto clicks his fingers and snipers shoot the vampires dead behind Guren. He proceeds to question how Guren has managed to find not just one, but three black demon prospects. He does not believe Guren's claim he found them by luck, and remarks that all black demons have been subject to human experimentation which have low success rates.
Guren takes his leave, but not before Kureto queries his reasons for assembling these black demon users, suspicious of a coup against himself. Guren dismisses his concerns, and with his hand on the hilt of his sword he points out if that were his goal he could accomplish it right now. Guren asks if he would want to bet that he couldn’t land a single blow. Kureto states that he knows Guren's weaknesses, namely love, friendship and honor. Kureto states that Guren not setting aside these emotions to lead is something that makes him stronger and holds Guren back. It begins to rain and overall, Kureto trusts Guren since he believes these qualities make it unlikely he would betray him. Guren suspects another incident where Kureto has taken a hostage and asks what he wants from him. Kureto wonders what the point of living in a world like this is, fighting extinction. With the world devoid of hope he notes Guren continues to build his military power; he wants to know his intentions. Kureto himself has a grand goal of recovering the world, even with the vampires having destroyed their communications network cutting off contact with everyone outside Japan. Kureto’s next step is not establishing contact, rather it is to destroy every last vampire in the country. Not only that, he will also crush other human organisations to put the world under the Demon armies control. The first step in this grand vision is to thin the vampire ranks by exterminating the vampire nobles, of which there are currently twenty five in Japan, and Kureto is aware of their locations. His hand has been forced to act now since he is also aware that in one month, the vampires will launch a full scale attack on Tokyo. He wants Guren to take his team and one hundred members of the Moon Demon Company to Nagoya where ten vampire nobles are located. Despite the declaration of trust, Guren knows that there is more to the plan that Kureto is not sharing. He receives a directive and is ordered to carry out the mission. Kureto wants a world where the vampires serve as human’s livestock and turn the balance of power in the humans favour.
Kureto departs and Guren is visited by an apparition of Mahiru who tells him not to be fooled as it is not Kureto the lieutenant general of the Japanese Imperial Demon Army’s, but her orders that Guren is supposed to be following. Principally because she is the only one who can make Gurens unspecified wish come true. Guren tells her to shut up and her shadowy essence returns to his sword.
Yu is stood contemplating the view on the roof of a building, Shinoa arrives and hazards a guess that Yu has spotted some girl taking off her clothes, unable to think why Yu would be staring so intently if not for that reason. Yu asks her whether it was true that he almost killed her, Shinoa asks him not to worry about it. Yu considers the possibility that Guren planned for him to lose control, something Shinoa has also contemplated. He asks her to promise to be by his side as Shinoa has returned Yu to normal after the transformation. Whatever Guren’s plans, Yu decides that he is going to stick with him, referring to him as family since the beginning. Although Yu has come to see the rest of his squad as his new brothers and sisters, he cannot leave Mika out as he remains as an important member of his family. Yu then decides that you don’t turn on a brother because he kept a secret from you, and also Guren promised that he would help get Mika back. Kimizuki agrees that Yu is right to not turn his back on family, related by blood or otherwise. Shinoa squad finalise an agreement and opt for the course of sticking with Guren.
A blood starved Mika makes his way to the throne room of Sanguinem to find Krul preparing her blood for him atop her throne. Happy to see him, she allows the sudden surprise of Mika grabbing her forcibly to drink directly from her neck. An understanding Krul tells him to drink his fill. Suddenly aware of what he just done he throws her aside and apologizes. It isn’t a problem and Mika presses as to whether he can get extra serum for when Krul is not around. Krul says that whilst she can give him as much as she wants, the effects will not last forever, that the day when Mika will have to drink from a human is approaching. He is told to wait outside until Krul is done but pauses. Krul asks if there was something else. Now that Mika is aware that Krul was supposed to kill him and Yu on orders of the Progenitor Council, he asks what she gains by not doing so. He questions her further asking why she would put herself at risk to save them. Angered by the possibility that Krul could end up hurting Yu, Mika declares that he will put a stop to it right now, but Krul is far stronger and regards him as a pet and so easily forces him into submission. Krul says eventually Mika will learn that the vampires are not as bad as the humans and then states that she likes both him and Yu as well. Mika does not believe it but is ordered to believe so without question. Krul nevertheless silently confides why she kept them both alive and whispers why she needs the Seraph of the End for herself. Krul shares her plan for a final battle where she will bring the strongest vampires with her herself to end the humans. She explains that to save Yu, Mika must go undercover from both human and vampire sides in the war. Failure in this secret mission will make Mika a traitor to both sides and the whole world will turn on him.
Shinoa comes to Guren who has drawn up plans for war in Nagoya city. She informs him that both Yu and Kimizuki have completed their training, succeeding in demon possession. Shinoa chooses now to reply to a question Guren asked before, still unsure she can only feel that for the fist time someone needs her. Before leaving, Guren shares the new mission with her and that the plan was to kill the vampires in Nagoya.
In a laboratory, Kureto and Aoi oversee scientists preparing tests that are being carried out on a restrained Mirai. The power is increased and black mist begins to be emitted from Mirai’s head as the voltage is further increased even after being informed that Mirai could die.
Differences with the manga
|Not shown.||The child spy Kureto sent to get information in Sanguinem is shown sending a letter to Aoi Sangu, who then passes it to Kureto.|
|Yu tries to fix his hair in the hallway. All of the Shinoa Squad boys lives in the same apartment building. Kimizuki and Yu are neighbors, and Yoichi lives a couple of doors down.||Yu tries to adjust his hair by looking at his reflection in glass doors just inside Shinoa's apartment building.|
|Does not occur.||Yoichi makes a comment about the food being okay since two girls are cooking.|
|Shinoa opens up the meeting by praising Kimizuki's cooking and housekeeping skills before announcing that he is gay, much to everyone's shock. Kimizuki tells her to quit making up lies. She opens the serious discussion after that but says they should continue to judge Kimizuki's cooking.||Not shown. Kimizuki sits at the table with the squad before Shinoa opens up the meeting.|
|Shinoa and Mitsuba are stabbed with speech bubbles through comments on their ability to set an omelet on fire.||They are stabbed with metaphorical forks.|
|The vampire prisoners wear different clothing, and they are locked within high steal walls with barbed wires. Kureto has them killed by sword.||The vampire prisoners are chained up outside the city and have intense sunlight beating down on them. Kureto has them shot.|
|No rain.||It begins raining while Kureto and Guren talk.|
|Guren specifically asks if Sayuri, Shigure, or another one of his aides will be tortured this time. When Kureto says he did not prepare anyone this time, Guren calls him lazy. Kureto says he is busy rebuilding Shinjuku after the vampire attack. Kureto eventually he explains that he knows where each of the vampire nobles in Japan are by training several children as spies and sending them to vampire cities. He says that vampires treat humans as brainless livestock and do not remember their faces or names.||Guren does not specifically mention anyone. The remarks are not shown. Kureto does not discuss his spies.|
|Not focused on.||Many birds are shown and focused on.|
|Kureto has a childish and charming smile when he announces his aim to take over the world, and even Guren feels a momentary urge to support him. Mahiru appears and reminds Guren that he is already following her. She does not say anything more, and Guren shows no reaction to her. Guren states that he is already following Kureto.||The smile is not shown, and Guren does not react as much. Mahiru does not appear until after Kureto leaves, and she says she will help Guren achieve his goals. She says different things than in the manga. He appears disturbed by her.|
|Kureto is not shown giving Guren written orders||Kureto gives Guren a directive note.|
|Yu and Shinoa do not leave in the middle of the meeting with his squad. Yu and Shinoa met before their match against Guren and wear their uniforms. Yu explains he is looking west because Mika should be in that direction since Sanguinem is under Kyoto. He convinces Shinoa to help him rescue Mika. When he takes Shinoa's hand, Guren arrives and teases them before beginning their training. Shinoa discussed how Yu and Kimizuki, the melee-type fighters, would be "knights" to protect the manifestation-type members of the team before they advanced their training and loosened the curses against their demons. Yu explains he is||Yu and Shinoa leave in the middle of the meeting with their squad. Yu and Shinoa go to the roof while he thinks about the experiment. Shinoa brings up her so-called "knights." Yu mentions looking west but does not explain that Mika should be in that direction.|
|Kimizuki only makes cracks about Yu's hair in the beginning.||Kimizuki keeps teasing Yu about his bedhead.|
|Krul is standing when Mika attacks her. The vial breaks dramatically.||Krul is sitting on her throne when Mika attacks her. The broken vial is shown afterward.|
|Mika wipes off his own mouth. Krul does not say anything about him being unable to drink her blood forever. Mika asks for a slightly larger stock rather than more stock, which demonstrates that he requires more of her blood than before. Krul teases him for already breaking one of the vials by being so rough with her. He looks up at her sheepishly. She orders him to report about the attack against the Shinjuku humans, and he demands an explanation about what went on during the Progenitor Council meeting. He brings up the Hyakuya orphanage and provides the explanation she gave him. Krul talks to him right there instead of ordering him to her chambers.||Krul wipes off Mika's own mouth before he does. Krul reminds Mika that he cannot live off of her blood forever and warns him about a day that will come. Mika requests more stock instead of a larger stock. Krul does not tease Mika. Krul orders him to go to her chambers. The rest of their conversation is now shown, and Mika only asks her about Yu.|
|Mika never charges at Krul, and she never calls him her pet. She brings him to his knees by intertwining her fingers with his and piercing her fingernails through his hand and making him bleed. She tells him she can easily extinguish a life as puny as his and that he is dependent on her blood. She addresses him as her tool. She asks if he will abandon Yu to his fate when human foulness is not limited to only one group. Echoing Guren's statement to Yu previously, Krul tells Mika to believe her. She says she is his savior, surrogate parent, and owner. She says he would have died years ago in that orphanage if not for her. She mentions going about her orders from the council since she has finished appeasing her "self-centered little son" after she explains her goals to him.||Mika moves to grab Krul when he asks her about Yu, and she calls him her pet. She twists his hand to bring him to his knees. Most of the conversation is not shown.|
|Krul tells Mika to protect his family from both vampires and humans. She tells him to "get lost" during the chaos and hide.||Krul mentions hiding Mika and Yu from the vampires and humans. Krul calls this a "secret mission." She warns Mika that the whole world will turn on him if he fails.|
|Not shown. She talks about someone needing her while sparing with Guren after he flings Yu off the rooftop.||Shinoa meets with Guren while he is planning his battle strategy. She talks about someone needing her.|
|Mika meets the other vampires during the daytime on the surface.||Mika meets them by the planes in the anime-only plane docking area.|
|Mirai Kimizuki is not shown until after the Moon Demon Company is in Nagoya, and she is being transported in the air. She screams and begs for Kureto's scientists to end it and kill her already until wings sprout from her back. There is no strange black mist.||Mirai is shown already. The experiment is taking place in the base instead of in a carrier transport. She exudes some black mist and does not scream like in the manga. She appears still and unresponsive.|
List of characters in order of appearance:
Anime images provide a visual overview of the events of Episode 15 with depictions of the characters, Seraph of the End world, scenarios, artistic style among other areas.
|Episode 1 • Episode 2 • Episode 3 • Episode 4 • Episode 5 • Episode 6 • Episode 7 • Episode 8 • Episode 9 • Episode 10 • Episode 11 • Episode 12 • Episode 12.5 • Episode 13 • Episode 14 • Episode 15 • Episode 16 • Episode 17 • Episode 18 • Episode 19 • Episode 20 • Episode 21 • Episode 22 • Episode 23 • Episode 24|