While Arima and Kerberos were conducting a battle of wits, Karez managed to open a small breach on the veil of darkness which revealed an unknown scenery. He grinned and enlarged that opening as much as he could.

The gate made an outlandish sound as the bones splintered. Karez stepped through then looked back from the other side of the gate before extending his hand.

"You stay, Hound…" He muttered and the doors of the Hell Gate were suddenly closed. The red skull reformed and its golden eyes flickered before the gate began to slowly dissipate like a mirage.

***

At the same time, Kerberos's massive body quivered and his three pairs of eyes widened. Even the snake was shaking as it lost strength.

Arima didn't know what was happening but he took the occasion and drew Ira before shooting at the snake. Those bullets were surprisingly powerful and destroyed the eyes of the snake. The reptile hissed and backed away.

Arima then tightened his grip on Superbia and observed Kerberos closely. He furtively waved his right hand a bit and a black smoke covering it was dispersed. He had been ready to use his undead form and although the venom seemed to be able to even affect his bones, it would have given him some leeway to escape by getting rid of his flesh. But Kerberos's actions made him stop.

The Hellhound was currently in a state of shock which was translated on his heads by his three different expressions.

"Impossible…"

Arima frowned and slightly lowered his rifle. He couldn’t believe that this hound would suddenly start putting up an act. "Hey, what are you doing?"

Kerberos’ expressions appeared to be conflicted. His look abruptly lost all of its previous combativeness.

"…My connection with the gate has been severed," he could only answer. "Someone forced the gate to close and leave me behind."

Arima heard him and felt extremely confused. "What does that mean for you?"

"I’ve temporarily lost my privileges. I can't be the Guardian of the Hell Gate if I don't have a gate to protect…" Kerberos tried to loosen his body but with Karma piercing him, he just groaned in pain and gritted his teeth. "I’m also liberated from my obligation…"

When he added the last part, Arima shook his head and sighed. His silver hair slowly faded away, his eye returned to normal, and his resonance ended with Night reappearing in his human form beside him. At the same time, his clothes were restored and his empty left sleeve fluttered with the wind.

"Karma," Arima called and the harpoon became a red light that flew to him and reappeared as a red-haired woman.

"So, basically, you won’t try to destroy this planet anymore, correct?” He snickered. “If you want me to spare you, why don't you say so?"

Kerberos huffed. "That wasn't my intention at all," he replied and freed himself of the ice restraining him after Arima voluntarily weakened it.

"Now, let's be fair. Give me the antidote. If I choose to take care of this poison by myself, it will take weeks and on top of that I’ll need to be immobile," Arima demanded.

Kerberos waved his tail. The head of the serpent was reattached and his sigil glowed. A green hue covered Arima who smiled and nodded. "Thanks."

“What else can I do, honestly?” Kerberos retorted. Night shrugged and Karma chuckled.

"What do you plan to do now?" Arima asked after the poison had entirely been expelled from his body.

"I have no idea…" The huge beast answered with a difficult expression. "I can't return to Hell with my current power. Maybe I'll just wander around in the different worlds and wait for an occasion to go back somehow."

Arima mused. "What's your strength now, without being in Hell?"

"Right now, I should be between the Fifth Sky and the First Divine. In Hell, I'm normally at the Second Divine," Kerberos answered and gazed at Arima.

"When you fought me, you were around the same level as me. But you didn't show me everything, right? I’d say that the maximum level you can reach is near the First Divine. You hid many trump cards from me, didn't you?"

Arima laughed lightly. "Yeah, you're right. I mean, you were fighting with a handicap so big since the beginning, I wasn't trying to be impolite. Furthermore, I’m 100% sure you also have a trump card. What’s wrong with keeping mine hidden?"

Kerberos snickered then thought of something. "Can't you bring me back to Hell? Your magic is really impressive. I feel like you’re omnipotent. I’m sure you could make a gate to Hell, no?"

"Possibly,” Arima smiled. “If you were to help me, then it would be easy actually. But why would you go back to Hell? It's not like you gain anything by going back there."

Kerberos shook his heads. "No, I was born in Hell and protected the gate since then, it's my duty to be there…" He paused. "Hell is also a lot more important than you may think. I need to find out who cut my connection with the gate. That person most likely went to Hell for some reason. And he could cause great damage."

"Ah," Arima remembered something and raised his voice. "I know the name of the man who summoned your gate," he said and Kerberos’ ears perked. "Ojure Karez."

Kerberos’ body tensed and his eyes widened when he heard the name. "Ojure? That escapee!?" He bellowed in shock and Arima covered his ears, so did Karma and Night.

"Please stop that. My eardrums have suffered a lot these days,” Arima said while rubbing his ears. “What do you mean by escapee?"

"Six hundred and fifty years ago, one man discovered the emplacement of Hell's core. He robbed a part of its power then fled immediately after," Kerberos told.

"The core?" Arima reacted to that word.

"The core is basically the heart of Hell. If the core is destroyed, Hell will collapse," Kerberos explained with an anxious tone. "The collapse of Hell means the destruction of all the lower worlds. Hell and Heaven are two opposite Original Lands, maintaining most of the worlds in place together. If one of them disappears, all of those worlds will be destroyed as well."

"Six hundred years ago, we assumed that Karez's goal was to destroy Hell. But, even if he failed, he still managed to take a part of the core's energy with him. He must have overpowered the gate and cut my connection with that same energy…"

Arima quietly listened then snapped his fingers. They left the dimension and reappeared in the middle of the crater made by the gate when it opened.

"Do we still have time before that man takes action?" Arima asked.

Kerberos nodded. "The time flows differently. A day here barely represents an hour on the other side. And considering the time it should take for Karez to prepare, we should still have around a few months in this timeline."

"It's fine then. I only need a month. Just come with me. I'll pay a visit to Hell when I finish my business here," Arima said and started walking toward the PA.

Kerberos blinked. He pondered then looked at himself. He was too big, definitely too big. Maybe in the action, people might forget it, but Kerberos was an eighty-meter-tall beast. If you put Arima and him beside each other, Arima would barely look like a small insect.

Ultimately, Kerberos promptly changed his form and became a one-headed small dog pup with a snake for tail before jumping on Arima's shoulder. Night smiled wryly as he looked at the pup on his partner’s shoulder.

"That's how I looked like?" He uttered. Karma giggled whilst nodding and he groaned.

"Oh, yeah. I haven't introduced myself yet, right?" Kerberos remarked and Arima nodded.

"Now that you say it. I'll start then. I'm Arimane Blade, you can call me Arima."

"I'm Night Bahamut, his soul beast," Night followed.

"I'm Karma, his sword," Karma introduced herself with a smile.

Kerberos nodded. "I'm Chulainn Kerberos, nice to meet you," he said and Arima was a bit surprised.

"I never heard of that name in your legends," he remarked and the small dog just shrugged and the serpent he had for tail tilted its head.

"You don't expect our first names to be recorded in mythology books, right? Not even to mention the fact that the fine details are always different depending on the world. Chulainn is how my father called me and that's all I know. I’m aware though that I was named after a certain hero," he responded and Arima smiled.

"Fair enough. That name is quite nostalgic for me in fact."

“Hm? Why?”

“My mother’s name also came from the same legend.”

Chulainn hummed and Arima’s two soul companions showed some interest. But Arima didn’t develop on the subject and they rapidly arrived at the PA. Most of the students had left and his own class wasn't there too. He knew where they were but he decided to take his time and discuss with his new friend before going to find them.

***

"Arister Zeola…" Ofia mumbled as he looked at Arister from afar.

When he revealed his true name, Ofia was astonished. She knew about that name. She mentioned it to Arima and when she did so, he only said that it wasn't a problem. Never did she expect that another Z rank mercenary was actually hidden in her class as a student.

"Hey, princess, don't lose focus," Arister uttered and Ofia hastily gathered herself, flustered. She focused again on the situation. She analyzed the view she had and then sighed.

"How long are we going to continue this?" She softly complained. She, along with the rest of class, was fighting against a horde of monsters that escaped the dungeon that Arima purposefully left.

The students were scattered around the place and battling the monsters, some were in a group and some were alone. It really looked like a battlefield. Of course, when a stronger monster appeared, either Lanya or Arister would take care of it to avoid any incidents or casualties.

Ofia conjured a bow and fired arrows made of light magic as she was flying with her cockatrice wings. That's what Arima had advised her to do. She was suited to become a really good support and long-range weapons such as a bow were a perfect fit for her. Her analytical aptitude was also the best in the class and she could act effectively to help her classmates in critical situations.

She oversaw the battle and observed everyone’s condition. There was Balan who was casually making use of space magic to send attacks, physical as well as magical, back to the source.

Lena, who was in her harpy form, would plunge toward the ground from time to time, and mow every monster with her wings and wind magic.

Isla was candidly cutting monsters apart with water and ice whilst keeping a smile on her face.

Irian went wild in the middle of the horde in his bear form and could reap the lives of countless monsters with a single wave of his claw. Arima himself had affirmed that Irian’s physical ability alone was around the eighth level after his resonance.

Melody was working together with a beautiful green deer. The two of them were teaming up together instead of resonating their souls. Melody had greatly improved her control over gravity since the training session with Arima. She now could cast gravitational blades and Arima even considered teaching her a simplified version of the Second Destruction Art.

Of course, even if she were to completely learn it, she wouldn’t be able to reach the same level as Arima, effortlessly destroying a planet, before at least a decade.

The next one was Gaodu. To be fair, his ability was awfully average compared to the others but he was making good use of his spirit magic; choosing the element that was perfectly suited for every situation.

And finally, Ferzia, the most eye-catching one of the bunch. She simply was a monster herself on the battlefield. She mainly used a great sword to fight while thunder and lightning rumbled around her. Her actual strength was at the eighth level, but she had also made a contract with a Thunder Wolf when she got her hands on Arima's soul contract. It allowed her to reach the ninth level and augment her lightning magic. The Thunder Wolf was also a beast rumored to be extremely fast and her speed was rather impressing.

As Ofia was watching and supporting her classmates, especially Irian who was exhaustingly careless, she suddenly sensed something and turned toward a certain direction.

Three figures appeared beside Arister. Two of them were Karma and Night while the other was obviously Arima. The moment Ofia saw him, she gasped in shock. His left arm had been severed and his left eye was burned along with a whole part of his cheek. Even though they had already cicatrized, Ofia noticed the severity of the injuries and she never thought that she would see her teacher in this state.

But at the same time, she realized that the fresh scars on his face were exuding some sort of smoke and gradually disappearing. Apparently, it already had started healing, which was quite staggering in its own right as well. Ofia also spotted a black small dog on his shoulder. She was curious and approached them.

When she got closer, she witnessed Arister looking back and forth between Night and the small dog on Arima's shoulder.

"That's not Night… right? Hey, don't tell me," Arister pointed at Chulainn with a trembling finger.

"Yeah, he's the fellow who came out of the gate," Arima nonchalantly replied and Arister's jaw dropped. Even Ofia had no other reaction but to gape and cover her mouth.

"What about your arm?" Lanya arrived near them and gently asked Arima. He rolled back his sleeve and revealed a skeletal arm, slowly being covered by a new layer of flesh.

"It's faster to heal it with death magic. So, it should be back entirely by tomorrow I think," Arima once again said something outrageous and Ofia didn't know how to react anymore.