"They're here! Haruta-kun, activate your Astral Vision!"

Seiji instantly activated [Astral Vision] upon Natsuya’s reminder.

He actually hadn’t mastered this spell yet. He was casting it with his bonded spirit’s a.s.sistance.

Seiji’s eyes instantly turned blue, and everything within his field of vision was also tinted blue. The world around him became much sharper; it was as if he were wearing high-tech night goggles.

[Astral Vision]... This type of vision rendered the school in a completely different light.

Spell formations of various sizes were engraved on each of the school buildings, and some were revolving slowly. All the spell formations were radiating differently colored light.

The largest spell formation was on the school grounds. It was so large that it exceeded the boundaries of the school grounds, and even with his enhanced vision, it was impossible to see it entirely.

Apart from the formations, there were many other defensive measures: interlinked chains which hovered above the ground; strange, totem-like objects; and flying lanterns, dolls, talismans, and sheets of paper. There were also a variety of other mysterious objects that were either flying in midair or following fixed paths. The chaotic scene made Seiji feel dizzy.

But what stood out the most of all were the various demons and spirits either guarding specific locations or roaming around.

There was a huge, large hammer-wielding one-eyed monster with green skin and a bald head.

There was a pitch-black demon that looked like a growth of aquatic weeds, and its many tiny eyes were opening and closing rapidly.

There were a team of skeletal warriors clad in tattered armor and wielding rusty weapons—Seiji a.s.sumed these were grudge-bearing ancient spirits from some battlefield.

There was a smooth, completely white abnormal-appearing demon. It was lanky, and in the place of legs and arms, it had four sharp blades. It lacked any facial features, and its head was also blank, save for a black talisman attached to the top of its skull.

Witnessing all these sights was a truly eye-opening experience for Seiji.

Many of these ent.i.ties' appearances were inside of his expectations and were rather normal, while others seemed incredibly out of place.

There were a few that he really wanted to comment on—especially that smooth, white demon. Seiji felt that without that talisman on top of its head, it would belong in a horror movie rather than a mystical school!

There were far too many different types of demons and spirits for him to ask Natsuya about, which was why he didn’t ask anything. There would be plenty of time to chat after the duel.

At any rate, under [Astral Vision], the school was far different from how ordinary people saw it. Only after he personally witnessed this sight did Seiji finally realize what the president had meant by calling the school her "castle."

This was indeed Natsuya’s castle with her as its Yin-Yang Master; this was indeed her well-defended territory.

However, the castle was currently under siege.

A huge number of demons approached both from the ground and the air!

The majority of them were red-skinned demons sporting horns and wings—they were the same type that Seiji saw when he was dispelling the amnesia spell on s.h.i.+ka.

This time, there weren’t a ridiculous amount of demons like in the soul layer, but there had to be at least several thousand pouring towards the school like an unstoppable tidal wave.

When they got close enough, various spell formations suddenly lit up and shot orange lasers at the demons, vaporising most of them into thick, smoky mist.

The remaining few demons continued to press onwards.

Yet more spell formations lit up, filling the courtyard with beams of multi-colored lights that shot into the ranks of the remaining enemy demons.

Thanks to yet another baptism by lasers, only a few dozen demons remained.

After they finally entered the school grounds itself, the barrier covering the school destroyed many of their number, leaving only a pitiful dozen or so that were instantly mopped up by the patrolling skeleton team’s swords and arrows.

Seiji rubbed his chin in contemplation. 'This feels like a tower defense game.' 

In actuality, that was probably what this was. The enemy’s goal was to destroy the critical defense locations here, while Natsuya needed to protect the school, which was basically the exact goal of a tower defense game.

Not only that, if Seiji thought of the Yin-Yang Masters as summoners and treated the Spirit-branded Retainers as champions… this was basically freaking League of Legends!

Come, let’s shout "Demacia" together!

Seiji coughed. 'I shouldn't get too excited.'

Seiji, a temporary Spirit-branded Retainer and a beginner to Yin-Yang Master warfare, felt that he could only be the equivalent of Garen if he were compared to a League of Legends champion.

The starter champion, who was one of the cheapest ones to buy, had abilities which only needed a cooldown and no mana. He was easy to learn and had a balanced attack and defense but had a few obvious weaknesses. 

'Hey, that means I should… Whoops, I went off on too much of a tangent.'

Seiji hurriedly made himself come back to his senses.

He saw that a new wave of demons had already arrived en ma.s.se. They rushed at Natsuya's defense formation frenziedly.

How long would the enemy’s attack and their defense last? Just as he wanted to ask, he heard a thud from the side.

"It’s Rana."

Natsuya gave only that simple statement before she instantly jumped off the fence and ran towards the right.

Seiji followed her.

Since both of them were using the Body-strengthening Spell to cover ground quickly, it wasn’t long before they saw what was going on.

Rana was currently battling with a man wearing strange black clothing.

The current Rana's appearance was a far cry from how Seiji was used to seeing her. Her body was shrouded in a dark red mist which turned her invisible. Her eyes were especially bright in the mist, and they shone green and blue, leaving two bright color trails every time she moved.

With both hands and feet on the ground, she moved about as if she were a real cat. She was agile, flexible, and unpredictable; sometimes she appeared to flow like the wind, while at other times she was as fast and deadly as lightning.

The man was clad in what seemed to be a special force uniform. Every piece of his clothing was pitch-black, and his head was covered with a black hood. It was standard ninja attire, disregarding the two a.s.sault rifles—or two mystical firearms which resembled a.s.sault rifles—that were currently unleas.h.i.+ng a hail of bullets at Rana!

But it was useless.

Rana avoided the majority of the bullets. The few which made contact with her were deflected by her mist, leaving her unscathed.

Rana was darting into the man’s blind spots before launching a lightning-fast offense.

The man was barely managing to hold on, and he tossed one gun down onto the ground, attempting to change his ineffective weapon for a better one…

*Pound!!*

Just as the gun left his hand, Rana charged at him at an unbelievable speed and headb.u.t.ted him, sending him soaring into the air!

The man had obviously been injured by this. He panicked as he lost his balance and was unable to pull out a new weapon…

*Pound! Boom!! Smack!!!*

There were three successive midair thuds.

The first two blows were too quick for Seiji to see clearly.

However, he managed to capture the last move. In the last blow, Rana stomped both her feet onto the black-clad man’s head, sending him hurtling into the dirt like a meteor!

After a tremendous crash, the black-clad man was buried into a huge pit with only his lower half sticking out.

First blood! What a cla.s.sical death… whoops, he wasn’t dead yet.

In Seiji’s [Astral Vision], the black-clad man still showed up as a color, which meant that this man’s soul was still present, and he hadn’t died yet.

"He’s Okubo’s temporary Spirit-branded Retainer," Natsuya said after carefully examining the man. "His combat clothes are of the scouting type, which means that this retainer’s role consists of only scouting… He probably sneaked in during the demons’ attack while the spell formations were preoccupied in order to find out the specific locations of our critical defense points."

"Did he succeed? Er… what I mean is, is it possible that he already discovered the locations and sent out the information?"

"It's not possible in such a short time."

"Oh… what should we do next, then?" Seiji glanced at the enemy retainer still buried headfirst into the ground, before looking back at Natsuya with an inquiring gaze.

"Pull him out and I’ll seal his powers and leave him here."

"Is that really alright?"

"It’s fine; he won’t die."

Natsuya turned around to look at Rana, and Rana waved her paw… whoops, her hand, then turned around and ran off, blending into the shadows.

After Seiji and Natsuya took care of the black-clad man, they returned to the rooftop.

They were just in time to witness the defeat of the second demon wave.

"Are there going to be more?"

"I doubt it. We’ve already defeated his scouting retainer, so there’s no more meaning to such an attack anymore unless he wants to waste his Spiritual Power and Mana."

"Then what will be…"

Before Seiji could finish his question, he saw a car turn around the street corner and head straight for the school.

It was a funeral home car, the one also known as a hea.r.s.e!