Zairos was an Ancient Undead, freed by Yona from the glacier where he had been trapped. Thanks to him, Zairos awoke from a long slumber and joined the legion, but it was during the 7th Legion’s golden age. Many Ancient Undead already stood by Yona’s side. As a latecomer, Zairos’s position was hardly significant.

Thus, he sought to prove his loyalty to Yona, who had given him a new life, and did whatever he was told. Killing. Destroying. Burning. This time was no different. Zairos had completely wiped out the monsters Yona had ordered him to kill and was walking back with their heads in a net. He hoped for praise, having completed his orders. But then...

A human woman was hovering next to Yona, his commander. She seemed to have fallen for Yona after a chance encounter in the western region and had been following him ever since. He’d heard she was a powerful necromancer herself.

"Yona," she cooed.

"About Zairos, though."

Zairos, who had been about to hurry over with his report, stopped in his tracks as his name came up. He withdrew his Jet-Black and concealed his presence.

"Yona, your legion has plenty of competent captains, right? But Zairos... he seems a little strange."

She paused for a moment.

"You tell him to save people, and he captures all the nearby villagers and a passing band of thieves, then locks them in a cave. You tell him to bring you someone in red clothes, and he wounds people just to stain their clothes red. He follows orders in the strangest ways, and he always interprets things in a way that makes the situation worse."

She shrugged.

"It’s almost pathetic watching you struggle to clean up the messes he makes. Why do you even keep him around? He’s just... so weird."

Zairos suppressed the urge to tear the woman to shreds and waited for an answer. Yona, sitting on a rock, laughed.

"You’re right."

Zairos dropped the net he was holding. The monster heads inside fell to the ground, rolling and scattering everywhere.

"Zairos isn’t flexible, and he’s not particularly smart. He can only do one thing at a time."

Finding it too unpleasant to listen any longer, Zairos was about to turn and walk away when he heard it.

"But."

At that moment, Yona’s voice was crystal clear amidst the surrounding noise.

"He’s the one who gets that one thing done, diligently and without fail. That’s why I trust Zairos more than anyone."

In that instant, with just those few words, Zairos felt he had been saved. An emotion he had never felt in life or death. A single phrase that seemed to compensate for all the years past. The acknowledgment of another. That was what Zairos had been missing.

"For Lord Yona alone!" Zairos had declared.

After that, Zairos, who had even unlocked his Geheim, pledged absolute loyalty and carried out any order from Yona.

"Zairos, stay here and guard our retreat. I’m counting on you!"

"It’ll be a dirty job, but you’re the only one who can do it. Wipe them out without a trace."

He didn’t shy away from rough and difficult tasks. Only for Yona. Zairos knew he wasn’t smart and his judgment was poor. He didn’t know how to cut corners and lacked flexibility. But if nothing else, he carried out the one thing Yona instructed him to do more reliably than anyone else. He was slowly gaining the acknowledgment of Yona and the rest of the legion, but...

"Zairos. I need you to stay and protect the North."

The problem began when they arrived in the Kalos North.

"In the legion, you and the Snow Demon Unit are the only ones who can navigate this frigid terrain. The duration will be about five years. It could be shorter, or it could be longer."

Yona placed his hands on both of Zairos’s shoulders and spoke seriously.

"Can you protect the North for me?"

Zairos accepted. He was in charge of the dirty work, after all.

And so, the 7th Legion departed, and only Zairos remained in the North. For an Ancient Undead who had existed for a long time, five years should have been a fleeting moment, but five years without Yona was longer than he had imagined. Still, he endured. He persevered. Yona expected him to protect the North, and so he would meet that expectation. He could never disappoint Yona.

The Northern God persistently created undead and invaded Vilkenos, and Zairos stayed in the Frost Field, fighting against it. Yona would return soon. If he just held on a little longer, Yona would release him from this duty. Zairos endured the deep loneliness, taking comfort in the Jet-Black of Yona that flowed through his body.

However, at some point before the promised five years had passed... ’snap’.

Zairos felt his contract with Yona break. He could no longer feel Yona’s Jet-Black. The mental channel he had kept open to respond when Yona came was also gone.

’[Aaaaaaaaaaaaaaaah!]’ he roared.

’Yona had abandoned me.’

He remembered the human woman’s words. "It’s almost pathetic watching you struggle to clean up the messes he makes. Why do you even keep him around? He’s just... so weird."

’Did he really abandon me? Am I no longer needed? Was that woman right after all?’ Zairos denied it. ’It couldn’t be. Something must have gone wrong.’ But even after the promised five years had passed, Yona did not come for him.

’That’s it! It’s because I haven’t fully completed my orders yet!’

Yona’s order was to ’protect the North’. And the greatest threat to the North was the Northern God. As long as the Northern God existed, he wouldn’t be protecting the North in the truest sense.

Zairos, who had only been on the defensive until then, gathered his full strength for the first time and went on the attack. A battle with the Northern God. Despite being outnumbered, Zairos managed to break through the Three Brothers and reach the Abyss. And then... he killed the Northern God. Covered in black blood, Zairos roared.

’[Lord Yona! I did it! I have brought complete peace to the North! I have perfectly carried out the mission you commanded!]’

But even after eliminating the Northern God, Yona did not come to see him. ’I carried out my mission. I protected the North completely. I have the right to be acknowledged. So why?’

Zairos fell into despair and crumbled.

"Yona has forgotten you."

Then, a dark voice whispered.

"Yona has competent Ancient Undead to replace you. He has forgotten your existence."

"Do not speak so carelessly!" Zairos yelled.

The dark voice continued to speak inside Zairos’s head.

"Protecting the North was the mission and duty you were given. But the North has become peaceful, and you, its protector, have served your purpose. So where is your use now?"

He was at a loss for words.

"You must make Yona come find you again."

The pupils of the despairing and broken Zairos trembled.

’[...How on earth can I make Lord Yona look at me again?]’

"Plunge the North into crisis once more."

The dark voice said.

"Is it not simple? Return everything to the state it was in before you received your orders. If the North is in crisis again, Yona will finally remember you and seek you out for your usefulness."

"The North... in crisis again."

"No one acknowledged you, the one who stayed behind and fought so steadfastly for the North."

The dark voice grew louder.

"So show the world! Show them what a great deed you accomplished!"

---

After that, Zairos took the power of the Northern God. He established a new Abyss and gathered monster corpses to create an army of undead. The Northern God had returned. He had planned to plunge the entire continent into fear and thus imprint his existence upon Yona, but an unexpected variable held him back.

"Assemble."

The girl had grown. The other one who had made a pact with Yona in the North, besides Zairos. ’Jin Arscalt’ united the North and rebuilt the 2nd Legion. During the five years Zairos had bought them, the young Grand Duke, who had learned to wield the power of Hate and the Bow of Gale at will, unleashed her unprecedented talent and blocked the Northern God’s attacks.

After a great victory in the first war, the young Grand Duke raised an arm covered in bandages and shouted.

"I have risen to keep the promise made to my father and my benefactor! People of pride, follow me!"

The girl’s speech instantly galvanized the people of the North. And Zairos, too, heard that speech through his undead subordinates.

’What am I doing right now? Why am I fighting the girl Lord Yona told me to protect?’

Zairos’s clouded mind began to clear slightly. He first ceased all hostilities against the humans. The Grand Duke of the North also only defended her own territory and did not advance beyond it. A very brief peace followed, but then a deafening boom shattered it.

The variable appeared from the outside.

"Hahaha! To think there are magic crystal mines in the Frost Field! The rumors were true!"

Count Voldmont, a newly arrived overseer in the North, had invaded the Frost Field with his private army. With Zairos having halted all attacks on humans, the excited Count plundered the underground resources of the Frost Field. As if one or two mines weren’t enough, he even tried to attack the Abyss. That action strongly provoked Zairos.

"Look, Zairos."

The dark voice egged him on.

"Yona told you to protect the North. From what? From those who would shatter its peace. True peace will only come to the North when the humans are driven from this land."

The snake-like voice burrowed into Zairos’s broken heart.

"Both to make Yona find you and to uphold Yona’s command, you must become the Northern God and defeat the Grand Duke."

Thus, a new, long war unfolded in the North. The guardian who had protected the North, Zairos, became the new Northern God and invaded Vilkenos. And the young girl who had lost her father to the Northern God, Jin Arscalt, became the Grand Duke and defended Vilkenos.

As this long war raged on for over a decade, the situation entered a new phase with the arrival of Yona’s son in the North.

The clash of steel rang out once more as Simon and Zairos violently exchanged blows before retreating.

"Keuk!" Simon gasped, falling back. His chest felt tight, and his breath caught in his throat. His knees trembled as if they would buckle at any moment, and his consciousness began to flicker. If his concentration slipped even a little, he felt he would pass out.

[You struggle well, son of Lord Yona.]

Zairos let his sword of cold hang low, and as he made a motion to sit, the throne rose to support him. At the same time, the tentacles and undead of the Abyss swarmed to fill the surroundings.

"Ugh!"

Simon frantically dodged the attacks, brandishing the greatsword in one hand to spread its poison and hold on. But his Jet-Black had long since run out.

Zairos’s gaze fell upon the golden flag Simon was desperately holding. [I know that flag well.]

[It is the flag of that hateful Grand Duke who lives in Vilkenos. To use it, the tip of the flag must directly touch the target’s body.] He smirked. [The Grand Duke. I know she tries so hard, creating a suicide squad called the Standard-Bearers under the pretext of Northern pride, but you are alone here. Do you think you alone can touch my body with that flag?]

"Don’t insult the Grand Duke and her warriors, Zairos," Simon retorted, lowering his stance. "And it doesn’t need to touch you."

[What?]

’Thump!’

Simon kicked off the ground and charged. Zairos once again raised his arm, sending swarms of tentacles and undead to overwhelm Simon. Green poison burst forth from all directions. Zairos sat nonchalantly on his throne, propping up his chin.

[What do you plan to do with that trembling body!]

At that very moment.

’Corpse Explosion.’

A series of explosions erupted from the zombies Simon had summoned from his subspace. Zairos, who had been watching nonchalantly, tilted his head back.

’VWOOOOOOSH!’

Piercing through the black smoke of the explosion, the staff of the golden flag shot forward. Zairos smirked.

[How predictable.]

He rose from his seat and swung his sword of cold at the flag.

’Crack!’

The golden flag’s staff was cut in half. The severed staff clattered uselessly to the ground.

[It’s all over now. Die quiet...!]

’Whoosh!’

Just then, Simon, emerging from the other side of the smoke, charged at Zairos. Caught in a counter-motion, Zairos’s eyes widened. It wasn’t Simon who had thrust the staff from within the explosion.

’Since when!’

It was Pier’s arm, moving independently.

’Grab!’

Simon clung tightly to Zairos’s body. At the same time, Pier’s body disassembled into Bone Armor, linking and securing them together. Pier’s other arm morphed into a snake, binding Zairos’s arm so he couldn’t move it easily.

[Foolish! Without the Grand Duke’s flag, nothing can destroy my body!]

Simon’s lips curled up. "You were only watching the tip of the flag, weren’t you? If the flag can’t touch you!"

He pressed his left hand against Zairos’s chest. On the back of his hand was the image of a ’target’.

’Don’t tell me!’

Simon had stabbed his own hand with the tip of the flag.

’RUUUUUUUMBLE!’

Simultaneously, a thunderous roar erupted from the ceiling of the Abyss. The sky above shook as if a black bruise had formed on it.

[Stop, human! If you do that, your hand will also...!]

Simon’s eyes flashed. "A single hand seems like a cheap price to pay for defeating the Northern God, don’t you think?"

’SWIIIIIIIIIIIIIIIIIIIIIIIIISH!’

From the sky, the final strike, into which the Grand Duke had poured all her power, descended, guided by Simon.