Extra: Rimuru's Glamorous Life as a Teacher, Part 3

Extra: Rimuru's Glamorous Life as a Teacher, Part 3 (外伝：リムルの華麗な教師生活 その３) is the fifth OAD of the anime adaptation of That Time I Got Reincarnated as a Slime.

Synopsis
Rimuru and the Class S students have made it through the first exercise of the Freedom Academy's annual outdoor training event. Class S has arrived first at the destination, the mansion of Count Guratol, and now they're ready to begin the second exercise, a cave exploration... but awaiting them there are thieves who hope to kidnap the students and make a fortune returning them for ransom money. Just when it seems like Rimuru's students have fought them off thanks to the skills taught to them, they realize a monster is lurking among the thieves! This is the final installment in the brand new episode created by the original author, Fuse-sensei, just for this OAD release!

Summary
The students of Class S found themselves facing off with a phantom, formerly disguised as Count Guratol's butler, Gesdar. The sole remaining bandit, who had gone to fetch the butler, panicked, released his comrades, and fled alongside them.

The students prepared to fight, and Gale deployed his Beast Gnome to defend Tiss. Ken launched a furious assault, but the Spectre turned his blows aside with his bare left arm. He returned the favor with a single, devastating punch; Gale leapt forward and intercepted the blow with his shield, produced in Tempest from a scale of the dragon Charybdis. Though he blocked the strike, the spectre was able to force Gail back through sheer overwhelming power. The spectre seemed impressed, recognizing the quality of the piece.

Ken stepped forward again, this time flanked by Alice. Infusing his sword with light, Ken rushed the spectre again, while Alice flung her kunai; the spectre caught one between his fingers and stopped the rest in the space of a heartbeat with a flickering purple shield. He yielded ground to the oncoming Ken, while taunting him that his efforts weren't good enough, and reflecting that he ought to show Ken, and the rest of Class S, that "[his] strength is so superior, you cannot fight it!"

With a sudden flare of aura, the phantom appeared beside Ken and made good on his prior promise, dealing Ken such an impressive blow that he collided with Gale and sent both of them into the rocky ceiling, incapacitating them. Subsequently, he appeared before Alice, giving her the same treatment. All three were knocked out with those single attacks.

The phantom then revealed itself as "the highest of the lower-ranked phantoms" -- a Commander-class -- and exhorted the remaining students and Tiss to give up. Tiss begged Chloe and Ryota to run, but Ryota said it wouldn't work, and Chloe was certain Rimuru would come for them. Dedicating themselves to do all they could until that time, the two assaulted the spectre, and were promptly defeated.

Now alone, stripped of her guardian, the Beast Gnome, Tiss faced the spectre alone. He made no move to attack her; instead, he wondered what to do with her. At the moment, he explained, he didn't want to attract the attention of the Western Holy Church, because the Phantom Vanguard was still few in number. Realizing he was digressing, the phantom took the Enslavement Collar the bandits had left and offered Tiss a sadistic choice: in exchange for her survival, she must choose one of the five students to wear the collar -- and then slay the other four by her own hand. Should she refuse, he said, they would all die.

The phantom relished this moment: when someone admits to themselves that the most important thing is their own survival. The ugly sentiment this evokes is the ultimate feast for a being like him. As Tiss grappled with the decision, he gloats, anticipating her anguished expression when her "choice" is exposed for the falsehood it would be, and that they would all die there.

The phantom called for her to choose once again, and Tiss responds by declaring that she is a teacher, to the phantom's confusion. Tiss stated that her role model, Shizu, risked her life to protect the students of Class S, and that she wanted to be as much like her as she could. Tiss picked up a sword from the ground, declaring that even if she only lasted a single second, she would protect the children with all of her strength: she had already abandoned Class S once before, to a fate she had similarly thought hopeless, and she would not do so again.

At this brazen display of defiance, the phantom tossed the collar aside, declaring that he would put Tiss through as much pain as she could withstand; further, he would enjoy every moment of it, and would make her cry out for help.

Realizing her situation, Tiss mentally pleaded for someone, anyone, to help. She was beyond salvation and she knew it; she didn't care what happened to her, as long as the students were safe. As the spectre leapt, Tiss invoked a summon spell, and time stopped.

Something had responded, and it indicated it would accept Tiss' desperate request, "pending certain conditions." It declined to identify itself, but agreed to save the children, referring to a debt that it owed to Shizu that it should like to repay. With that, Tiss blindly agreed to the contract, heedless of its conditions. The figure was pleased, but chided Tiss to be more careful about so readily entering into a contract with a daemon.

Time resumed, and the spectre cut his leap short, sensing something. The summoning circle appeared beneath them, to the spectre's confusion and irritation. The circle disappeared, and the daemon interposed himself between the two parties. Based on his aura, the spectre noted with some alarm that he wasn't under Tiss' employ, but was instead autonomous -- able to act at his own discretion. The daemon complimented the spectre on his perception, remarking that he was quite intelligent "for a phantom."

Angered, the spectre claimed that if a girl like Tiss could summon a daemon, he had no chance to defeat him; a fatal mistake, as, unbeknownst to them both, the daemon who had responded to Tiss' summon was none other than Noir, the Primordial Black -- one of the seven Primordial daemons, the strongest among daemonkind.

Noir silently appeared behind the spectre and taunted him, mentioning that he would like to know what gave him that idea, but that he didn't have the time. He ripped the butler free from the spectre's control and asked the now-terrified spectre if he wasn't supposed to be strong. Transforming his right arm into a strange blade, he lopped off the spectre's arms with two quick strokes, then took him by the neck and held him up, struggling and helpless, before Tiss' terrified gaze.

Two more slashes took the phantom's legs off at the thigh, while he pleaded with Noir to stop. Noir simply raised him higher and choked the life out of him, dropping his amputated corpse to the ground a moment later. Noir nonchalantly dusted his hands and returned his attention to Tiss, proclaiming that he didn't have time to waste, but that despite appearances, he had been taking consideration to avoid unduly straining her with his appearance.

Noir demanded payment, asking if it were alright with Tiss. Clamping down on her emotions, Tiss closed her eyes and stated she was ready. Noir then stated his demand: that Tiss conceal his existence in utmost secrecy, not to tell another soul. The moment she breaks the agreement, Noir warned, her soul would then belong to him. Caught off-guard, Tiss confirmed that that was all, and Noir replied that his only interest was repaying his debt to Shizu; nothing else mattered.

Tiss then asked how she was meant to explain the events in the cave to anyone who might ask. Noir replied, as if it were the most obvious thing, that she should report that the spirit of light protecting Ken defeated the spectre. Tiss had no idea what Noir meant until the spirit of light separated from Ken's body and introduced himself.

With a final, lingering glance at Chloe, Noir took his leave, taking the Enslavement Collar with him. The elemental of light commented that, compared to what he had heard about Noir, he had apparently softened up quite a bit. Afterward, Tiss and the elemental of light took care of the kids, then returned to the city of Guratol, reconvening with the rest of the staff the following morning.

Class S reported the encounter and defeat of the thieves and phantom, ascribing the victory to Ken having beaten the foes in his sleep. However, the secret remedy that the count had worked to attain was lost, used by the thieves' leader -- meaning the count could not heal his ailing wife. Upon being asked about her condition, the count mentioned that her condition was stable, and that he had the best doctors treating her.

Upon querying Great Sage, it was unable to identify the illness plaguing Ulamuth due to a lack of data, stating that direct analysis would be required. Chloe then asked Rimuru whether they had any full potions; to the count's and Jeff's surprise, Rimuru asserted that they did, and asked if that was in fact the "secret remedy" needed. Rimuru questioned whether a full potion would even work on an illness rather than an injury; Jeff scoffed at this, and stated that if a full potion could restore entire severed limbs, it would surely work on an illness. Rimuru seemed surprised, but the count gloomily reported that some cases of treating an illness with a full potion resulted in death. All the same, he asked Rimuru for the potion.

Rimuru left the room and wondered if it would really be okay to treat Ulamuth with the potion, given the risk of death. Great Sage reported that the effect of a full potion was to accelerate cellular processes; however, this would include harmful irregular processes as well, which could explain the deaths. When asked on how to deal with that, Great Sage suggested resecting the affected area; following that, applying a full potion to the resected area will repair the body in a normal state.

Returning to the room, Rimuru presented the brothers with five full potions, and, after a session of bickering with Jeff, agreed to give them to the count on the condition that they be allowed to administer care to Ulamuth. On personal attendance, Rimuru confirmed Great Sage's supposition: had the count blindly administered a full potion, his wife may well have succumbed.

Rimuru took up a scalpel and, once more, confirmed Great Sage's instructions to cut out the affected area. Great Sage responded with a notification that the use of the Unique Skill, Predator, would make the task easier. With Guratol and others in attendance, though, this would pose difficulties. Instead, Rimuru surrendered control to Great Sage's auto mode in preparation.

Jeff left the room, pacing up and down the hallway and fretting about the operation's outcome. Chloe stopped him and, after a moment, took his hand in hers, assuring him that it would be alright, and to trust Rimuru.

Later, Guratol and Ulamuth took a walk in the garden; the count asked if his wife was alright; she responded in the affirmative, amazed that she was able to walk again and thrilled to be outside. The pair was observed by Tiss, Jeff, Rimuru, and a recovered Gesdar, similarly affected.

Rimuru congratulated Great Sage on a job well done; it responded by notifying them that its calculations were complete. Confused, Rimuru asked as to the nature of the calculations; apparently, a component in the wasp monster, Apito's honey is effective in killing malignant cells. Dismayed, Rimuru asked Great Sage to confirm that if they had simply fed Ulamuth honey, it wouldn't have required the operation; they coughed and refused to answer. Jeff, after a moment, thanked Rimuru profusely for their assistance with his sister.

The training exercise was nullified due to the presence of the thieves and the phantom, meaning nobody could declare victory. Rimuru and Jeff returned to their usual modes of interaction, and Tiss admonished the students not to grow up like they did.

It had been a good experience at the academy, but a fell wind would soon blow over the world, and Rimuru would find themself locked in another bitter struggle. For now, they are needed back in Tempest.

To Be Continued in Episode 25...

Characters
MAIN:
 * Rimuru Tempest
 * Great Sage

BRIEF APPEARANCES/CAMEO:
 * Shizue Izawa
 * Apito (Mentioned)
 * Milim Nava

RETURNING CHARACTERS:
 * Class S
 * Kenya Misaki
 * Ryota Sekiguchi
 * Gale Gibson
 * Alice Rondo
 * Chloe Aubert
 * Tiss
 * Gesdar
 * Unnamed Commander-class Phantom
 * Noir
 * Spirit of Light
 * Count Guratol
 * Jeff
 * Ulamuth

Locations

 * Kingdom of Ingrassia
 * The Town of Guratol
 * Mansion of the Domain Lord, Court Guratol
 * Freedom Academy
 * Jura Tempest Federation (Mentioned)

Trivia

 * This OAD is bundled with the special edition of Manga Volume 16.
 * This episode is written by Fuse, the series original author.
 * This episode is set during the events of Light Novel Volume 4: Human-Monster Interaction (Manga Chapters 40-55/Anime Episodes 20-23).