The next morning, the rookie competition is about to kick off, and the headmasters are all acting incredibly smug. They are convinced victory is assured because they each recently recruited a “mystery super-student.” However, when Arel walks in for the meeting, the awkward truth comes out: they all claim him as their star pupil at the exact same time! The headmasters are baffled, having no idea that Arel was attending every single institute simultaneously. But before they can grill him on his chaotic schedule, a massive commotion erupts at the festival. It turns out a giant slime is devouring monsters like a buffet and heading straight for the students.
Arel and the headmasters realize the situation is dire, so they agree to pause the interrogation and rush off to save the day. A student from the Red Institute tries to play hero by blasting the slime with fire, but his spells barely tickle it. Just as he looks like he’s about to be swallowed whole, Dione swoops in and airlifts him out of danger.
Arel‘s friends aren’t quite as lucky. While running for their lives, Colette manages to trip over her own feet and face-plants into the dirt, allowing the slime to catch up. Kaito and Kuufa refuse to leave her behind, so Kuufa casts an Ice Wall to block the path. Unfortunately, that trick fails miserably as the slime smashes through the wall in an instant. Kaito then steps up, trying a modified Eruption Blast he learned by copying Arel. It stalls the beast for a second, but the slime is otherwise unharmed and still very hungry. The monster launches its tentacles at the kids, but before they can be absorbed, Arel finally arrives and slices the tentacles to pieces. The headmasters catch up and tell the kids they’ve got this covered, ordering everyone to evacuate to city hall immediately.
Colette and the others understand the assignment and immediately bolt for safety. Arel pauses to ask the headmasters if they’re absolutely sure they want him to leave, considering he’s the only one who has done anything useful so far. The headmasters, suffering from a severe case of overconfidence, insist they’ll be fine because they possess “Supreme Classes.” Shrugging, Arel agrees and flies off, leaving the faculty to clean up their own mess.
Naturally, as soon as he’s gone, the headmasters realize they have no clue what they’re doing. This is the kind of intel Headmaster Black would usually have, but he’s missing in action. It seems the slime is immune to magic, but Headmaster White and Headmaster Blue decide to double-check that theory by firing their strongest spells anyway. Surprise! The slime is completely unharmed. Desperate, Headmaster Red and Headmaster Green combine their magic, hoping a wind-boosted fire attack will do the trick. Instead, the slime just eats the energy and grows even bigger. Nice going, guys.
The slime lashes out with tentacles, but Headmaster Yellow manages to block it with an Earth Wall, boxing the creature in to buy a few seconds of panic time. They finally realize the slime isn’t just immune; it’s an all-you-can-eat buffet for magic. Unfortunately, since they are mages who likely skipped gym class, magic is all they have. Headmaster Red suggests they just nuke it all at once to overwhelm it, but Headmaster White points out that would essentially turn the slime into Godzilla.
Meanwhile, Arel is hovering in the sky, watching the disaster unfold with a look of pure disappointment. He was hoping to see some cool, unique techniques, but everything they’ve done so far is basic stuff his dad taught him ages ago. With nothing new to learn, he’s barely paying attention. Raina asks him if he really plans to just hover there and watch them struggle, but Arel points out that they did explicitly say they could handle it. So, he’s going to let them try.
Mity tells Arel that taking down a Gluttony Slime is a nightmare, noting how bizarre it is to see one wandering around outside the Demon Realm. Arel presses for details, and Mity explains that the monster absorbs everything—especially Mana. Basically, the headmasters are idiots; they aren’t fighting it, they’re feeding it. Arel asks if physical attacks would work, but Mity warns the slime would likely just eat the weapon, too. Unfazed, Arel figures that a spell too dense to absorb—or a slice too fast to track—should do the trick. He creates a sword using alchemy and dives into the fray.
Meanwhile, the headmasters are watching helplessly as the slime marches toward the city center. Their magic is useless, and they are preparing to evacuate, but suddenly Arel drops from the sky and slices the beast. Mity is impressed Arel actually cut it, though the slime annoyingly reforms a second later. The headmasters are floored; they assume Arel must be a secret “Magic Swordsman,” but he casually corrects them that he is Classless. Naturally, they don’t believe him because that sounds insane. Arel realizes the slime is heading to City Hall to snack on the students’ mana and orders the headmasters to go protect them. They hesitate to leave Arel alone, but since he’s the only one doing any damage, they realize they have no choice but to obey.
Arel hits the slime with an Infinite Break attack, turning it into forbidden jelly, but the annoying blob reforms instantly. Realizing this fight is a total pain, the slime actually tries to run away, but Arel traps it in a massive box. To test a theory, he creates four golems and commands them to mimic his movements, hitting the monster with a Quadruple Infinite Break. Yet, even reduced to millions of pieces, the slime just starts reforming and climbing out of the box.
Since dicing it up failed, Arel decides to switch to magic. Mity finds this hilarious, assuming Arel is desperate enough to feed the magic-eating monster, but Arel ignores him. He begins combining magic circles from all six elements into one volatile cocktail. He learned this “Elimination Spell” from his dad, Leon, who explicitly warned him that a single slip-up during casting would vaporize him and everything within a mile radius.
Arel finishes the prep, but his mana tank hits empty, and he starts to lose control. Just as he’s about to accidentally nuke himself, a massive surge of mana flows into him from the headmasters and students back at city hall. Refueled, Arel unleashes the spell, completely deleting the slime from existence—along with a significant chunk of the city real estate.
As Arel lands, exhausted, the headmasters rush over in total shock. They scream that only a “Mage Lord” could pull off the legendary Annihilation Spell. Arel insists he really is just a Classless guy whose dad taught him a few tricks. Headmaster Red finally connects the dots: the only Mage Lord he knows is a man named Leon.
Headmaster Red asks if the “Leon” Arel mentioned happens to be his old classmate. Arel is surprised, but Red explains that Leon was the student everyone thought would run the place—until he quit after one year. The other headmasters suddenly realize Leon pulled the exact same “dine and dash” maneuver on their institutes, too. Arel explains that his dad simply attended each school, learned everything they had, and left to master all six magic types. This revelation absolutely crushes the headmasters, who spent their entire lives convinced that specializing in just one type was the path to glory. Oops.
While the faculty undergoes an existential crisis, Arel sneaks off to sift through the crater. He finds a surviving chunk of the slime and, instead of destroying it like a normal person, decides to form a Master-Servant contract with it. By the next day, he’s using the terrifying world-ending monster as a portable garbage disposal. Kaito and the gang barge in, asking if he’s really leaving. Arel confirms that he’s learned everything he can, but promises to visit. His plan is to head home, then travel to the City of Monsters to research his new jiggly pet.
Meanwhile, the Board Director is hyperventilating about losing their reputation booster. The headmasters point out that they can’t exactly force him to stay, considering he could vaporize them all without breaking a sweat. Suddenly, Headmaster Black pops up—literally—and tells everyone to relax. He suggests they just work together to train a new Mage Lord. The others are less impressed by the plan and more concerned that Black is now a ghost. He explains that the slime ate his body, but he used black magic to save his spirit. Conveniently, he leaves out the part where he was the one who caused the apocalypse in the first place.
