The morning air was sharp, biting at exposed skin, carrying the scent of frost and pine. Félix moved through the snow-laden valley with calculated steps, twin katanas sheathed yet alive with latent energy. Reports from the Corps had escalated: an Upper Moon demon, Akakami, had been sighted coordinating attacks across multiple villages. The sheer intelligence, cunning, and lethality of an Upper Moon dwarfed even the cleverest Lower Moons Félix had faced. Today's mission demanded not only mastery of Ice Breathing but full command over allies, battlefield manipulation, and moral judgment at a scale he had never experienced.
Tanjiro walked beside him, calm and measured. "Félix, an Upper Moon's strategy is unlike anything lower-ranked. They manipulate, deceive, and strike with precision. Your team must function as a single unit, and your decisions will determine life or death for countless innocents." Zenitsu muttered nervously, "Upper Moon… that's… terrifying…" Inosuke's ears twitched, teeth bared under his boar mask, excitement mingling with anticipation. Félix inhaled, Absolute Zero pulsing faintly in his mind, a constant reminder of the control and precision required.
The Upper Moon's presence was evident before sight: the forest exhaled an unnatural cold, branches snapping under invisible weight, shadows shifting unnaturally among the snow. Félix's pulse quickened with awareness, not fear. Leadership demanded composure, strategy, and precise execution. He signaled Zenitsu and Inosuke to cover flanks and secure villagers. The terrain was now as much a weapon as his katanas.
Akakami emerged silently from the treeline, crimson eyes scanning, calculating, exuding an aura of lethal elegance. Its movements were fluid, each step deliberate, a predator with centuries of experience honed into deadly precision. The Upper Moon's presence was immediately imposing, dwarfing previous encounters with Lower Moons.
"You are bold, young Ice Reaper," Akakami hissed, voice low and resonant, "to confront me directly. Do you know what is at stake?"
Félix met the gaze steadily. "I fight for the innocent. I will not allow you to harm them." His voice carried authority, calm yet unyielding. Leadership was not shouted—it was embodied. Tanjiro's gaze was steady, supporting yet letting Félix command.
The Upper Moon struck first, testing reaction and rhythm with swift, unpredictable movements. Félix executed Glacial Veil, intercepting the attack while simultaneously delivering Frost Fang to counter, forming a rhythm of offense and defense. Akakami's speed and cunning required Félix to integrate all ten Ice Breathing techniques seamlessly: Frozen Torrent, Diamond Frost, Ice Whirl, and Absolute Zero, manipulating terrain and controlling space with precision.
Zenitsu and Inosuke followed Félix's rhythm, striking at openings, protecting civilians, and creating pressure. Each movement was choreographed, yet spontaneous, adapting in real time to Akakami's unpredictable assaults. Snow erupted in crystalline sprays, frost forming barriers and traps, every strike a blend of beauty and lethality.
Akakami countered strategically, feinting toward Zenitsu while targeting Félix with a flanking maneuver. Félix pivoted, executing Frost Fang and Glacial Veil to shield allies, then unleashed Diamond Frost to immobilize the immediate threat. Absolute Zero radiated outward, subtly manipulating terrain and slowing enemy movement, buying crucial seconds. The Upper Moon's intelligence was evident, yet Félix's strategic foresight neutralized the advantage.
The battle intensified as Akakami adapted, coordinating multiple feints and attacks. Félix realized that victory required not brute strength but anticipation and orchestration. He adjusted positioning, guided Zenitsu's strikes, and subtly modulated Inosuke's chaos, turning unpredictability into tactical advantage. Ice Whirl and Frozen Torrent flowed into each other, creating barriers, manipulating space, and immobilizing strategic points.
A critical moment arrived when Akakami attempted to separate the team, targeting isolated villagers. Félix recalculated instantly, executing Absolute Zero to control terrain and protect innocents while guiding Zenitsu and Inosuke in coordinated strikes. Frost crystallized across the battlefield, immobilizing parts of the enemy's advance, while allies exploited openings created by precise control. The Upper Moon's attacks, though deadly, began to lose cohesion under Félix's command.
Yet Akakami's cunning remained formidable. It feigned retreat, attempting to draw the team into a trap within a narrow valley. Félix anticipated, signaling allies to adjust positions, using Absolute Zero to control choke points, and chaining Frost Fang and Diamond Frost to prevent overextension. Leadership, judgment, and mastery of techniques converged: timing, rhythm, and strategy dictated every decision.
Finally, Félix seized a decisive opening. Akakami overextended in a deceptive maneuver, presenting a narrow vulnerability. Félix executed a flawless chain of Frost Fang, Diamond Frost, and Absolute Zero, immobilizing the Upper Moon momentarily while guiding Zenitsu and Inosuke to strike with precision. Snow erupted in sharp crystalline shards, ice forming traps, and the battlefield fell silent for an instant.
Akakami recoiled, assessing Félix with a measured, calculating gaze. "You… are remarkable," it hissed. "Few slayers could integrate skill, leadership, and judgment so seamlessly. But this… is only the beginning." With a final, fluid motion, the Upper Moon vanished into the forest, leaving frost and shadow in its wake. Félix exhaled, lowering katanas, absorbing both relief and the weight of what had just transpired.
The Hashira descended from a nearby ridge, eyes assessing every decision and movement. "You have faced an Upper Moon directly and survived," he said. "You have integrated all techniques under pressure, protected innocents, and orchestrated allies with skill and judgment. Your reputation will grow, Félix. Remember, though—Upper Moons are patient and cunning. Today's victory is a lesson, not an endpoint."
Zenitsu collapsed, trembling but exhilarated. "We… survived an Upper Moon… I… I can't believe it!" Inosuke, chest heaving, removed his mask, grin wide. "This… this is insane! I didn't think we'd even see one, let alone survive!" Félix allowed himself a faint smile, acknowledging both encouragement and truth.
As night fell, the team returned to the village. Snow crunched under boots, frost glittered in the moonlight, and the weight of responsibility settled over Félix. He had faced not only a formidable enemy but the full strategic complexity of an Upper Moon. Leadership, judgment, and Ice Breathing mastery had converged into a new level of awareness, preparing him for future threats of even greater scale.
The forest beyond lay silent, shadows deepening, whispers of unseen forces lingering. Félix felt clarity, resolve, and readiness: Ice Reaper was no longer merely a warrior—he was strategist, guardian, and arbiter of consequence. The Upper Moon's shadow remained, a reminder of trials yet to come, of challenges requiring both skill and conscience.
The path ahead was uncertain, fraught with danger, but Félix had demonstrated mastery, leadership, and moral judgment on an unprecedented scale. Tonight, the region remained safe, civilians protected, and the Corps' confidence in him strengthened. Yet the Upper Moon's presence was a reminder: greater trials, higher stakes, and deeper strategies awaited the Ice Reaper who had begun to carve his name into legend.