Her physical and magical reserves fully restored, Iris gripped Apocalypse and stood ready to face Isis, who floated a short distance away.
Not a single word passed between them. After a brief silence, Alice—watching from the distance—raised both hands in a circle above her head. It was the signal that the spatial isolation barrier protecting the surrounding landscape was complete. It was also the sign that Isis was ready to fight at her full potential.
“—Guh!?”
In an instant, Iris felt an agonizing weight, as if her entire body were being crushed in a massive vice. Staggered, she forced her gaze forward to find Isis had quietly transitioned into a combat stance.
(I see. So this is the Magic Power of Death. A primal, instinctive terror. Had I not been in this body, the match would have been over before it began. If I had felt this in the heat of battle, I would have frozen on the spot. In that sense, experiencing her intimidation now was a stroke of luck... but even so, it is truly staggering.)
The mana radiating from Isis shifted from a pale blue to a deep, abyssal black. Her very presence became sharp and cold. She was the King who ruled over death, an absolute and unshakeable power. The earth trembled as if cowering before its ruler, and the air itself seemed to part to make way for her.
“Now then,” Alice announced. “Mock battle—begin!”
Even as the words rang out, Isis remained stationary, seated comfortably in mid-air. She communicated a single message with her eyes alone: I shall grant you the first move.
Iris understood instantly. She struck the ground with both palms.
(She dismantles magic, returning it to raw energy. At a glance, it seems invincible, but it isn’t an automatic reflex. It requires the steps of perception and execution. If I attack at a speed that exceeds her reaction time and a volume that her negation cannot match, there is a chance I can break through!)
Massive magic circles erupted around Iris. Ten, then a hundred, and finally a thousand. Drawing on the simultaneous casting she had seen Isis perform earlier, she pushed her mind to its absolute limit, nearly burning out her brain in the process.
“Ngh... Calamity Doombringer!!”
It was no longer a mere flurry of swords. Over a hundred million jet-black blades surged forward, so dense that not even a mouse could have slipped through the cracks. It was a massive wall of obsidian steel.
Even as she unleashed it, Iris knew Isis would likely dismantle the spell within ten seconds. She was already preparing her follow-up.
“...Die.”
“—!?”
Iris gasped. She had not anticipated that over a hundred million magical blades would vanish into nothingness at a single word. Against a serious Isis, a barrage of this scale could not buy her even a single second of time.
It was unexpected, but Iris was fighting one of the Six Kings. Unforeseen circumstances were to be expected. She poured a torrential amount of mana into Apocalypse. Alice had said Isis nullified nearly all magic—not all of it. There had to be things she could not neutralize. Iris gambled that it would be a strike of such extreme density and overwhelming volume that the negation could not keep up. She pinned her hopes on her newest technique.
“Devour everything! Beast of Tyranny—Giga Apocalypse!”
Technically, Iris’s reasoning was correct. Isis had a limit to the amount of mana she could dismantle instantly. When an attack’s output was too high, her negation could fall behind. The Giga Apocalypse, fired with mana multiplied several hundred times over, surpassed Isis’s speed of neutralization.
But that did not mean the attack would land.
“...Cocytus Infinity.”
In that moment, the world froze.
The swaying earth, the trembling air, and the jet-black beam of magical destruction—every single thing was arrested in time, locked in ice as a profound silence swallowed the world. Isis had spared Iris’s body, but the surroundings and even the staff Apocalypse were encased in the frost.
(What... what happened? I can’t move. No, my body, my magic, even my breath... everything is stuck.)
Her body was not technically frozen, but it was as if the very space required for motion had been sealed away.
“...This is my domain now,” Isis murmured. “Everything... freezes. Magic power... space... even time itself. And then the ice shatters... and everything becomes zero. Cocytus... Zero.”
“Guh—aaaaaaagh!?”
As Isis spoke, the frozen landscape and the massive mana beam disintegrated into fine dust. Only glittering ice crystals remained, dancing in the air.
“...What an incredible staff,” Isis noted quietly. “That it didn't break... even against my Cocytus Zero.”
“...Haa... haa...”
Iris knelt, gasping for air. Apocalypse was a Heart Tool; as long as her will remained intact, the staff would not break. But it was not an invincible shield. The weapon was an extension of her soul, and every heavy blow dealt to it inflicted psychic damage upon her. Panting, she stared at the ground. The outcome was clear to everyone.
“...Shall we... keep going?”
“...No. I have seen enough. I knew I couldn't win, but to think it would take only two moves—actually, only a single strike... The world is truly a vast place.”
“...You can get... much stronger. Right now... I was just a little... stronger. But... no one knows... what will happen next.”
“...You think I might actually win next time?”
“...I don't know. But... I think that as long as you don't give up... the possibility never becomes zero. If I had given up... on connecting with others... I never... would have met Kaito.”
Iris watched Isis smile warmly as she spoke of the man she loved. She had faced bitter circumstances and nearly surrendered many times, yet she had held on, and that persistence had led her to Kaito. Iris closed her eyes, reflecting on those words for a long moment.
Finally, she opened her eyes and smiled back.
“...Then, I have a request as well. Isis-sama, would you allow me to enter your service as a subordinate?”
“...Are you sure... you want someone like me?”
“It is you I want to serve. You possess the vessel of a true king.”
“...The vessel... of a king?”
“Yes. The fact that I wish to serve you now, and the charisma you possess that draws others to you—that is the vessel I lack. I see that vessel in you, Isis-sama, and I am certain you are worthy of holding my fangs. That is more than enough for me.”
Iris Illuminas was not an impolite person. She understood protocol and spoke with appropriate deference to those she respected. By addressing Isis as “-sama” and using formal language, she offered the ultimate proof that she recognized Isis as her master.
“...Yes... I understand. Thank you. I look forward to our time together... Iris.”
“As do I, Isis-sama.”
It was her first subordinate—something the other Six Kings had, but she had always lacked. As she took Iris’s hand, it marked the beginning of the Black Tyrant Star, the woman who would become the Head of the Death King's Subordinates and her most trusted confidante.
The Death King's Executive
The Black Tyrant Star: Iris Illuminas
Following this duel, Iris officially entered Isis's service. Being a diligent person, she committed fully to her new role, moving her residence to Isis’s castle. She spends her days serving there and her nights at Kaito’s home, tending the bar and spending time with Alice.
However, Isis’s excitement over her first subordinate is so extreme that within a few days, Iris was left wondering, "Wait, am I a subordinate or just a friend?" Since there isn't much formal work to do, she spends her days as a companion—drinking tea, reading books, and training alongside Isis. She would find herself questioning the definition of a "subordinate" many times in the future.
With access to the castle’s massive library and tutelage from both Isis and Alice, her strength grew rapidly until she truly earned her place among the elites of the Six Kings. Eventually, the Head of the War King's Subordinates began visiting for "play" (training) sessions, making the castle a much livelier place—much to Isis's absolute delight.