In the vast expanse of the training arena, littered with remnants of past battles, Whis stood calm and poised, his celestial aura radiating tranquility amidst the impending chaos. Today, he had chosen to train two formidable fighters, Kaiba, the God of Fear and Death, and Kairo, the Unmatched Soul of Will and Pride. Both possessed immense abilities and an insatiable drive to excel, and today, they would push their limits against him. Whis signaled, and the atmosphere shifted dramatically. The air vibrated with tension as Kaiba unleashed his first attack, summoning Radiowave Energy Blades that sliced through the air with a piercing shriek. Waves of distortion emanated from his body, creating an unsettling glitch effect that rendered him both eerie and powerful. The blades screamed as they ricocheted off Whis's protective barrier, creating explosions of energy that lit up the arena in blinding flashes. "Nice try! But you’ll have to do better than that!" Whis laughed, his voice echoing effortlessly. Kaiba smirked, his red eyes glimmering with sadistic delight. With a flick of his wrist, he activated his Dismantle ability. As he punched forward, the air warped, nullifying the weaker elements of Whis’s defensive magic. With every move, he became a living nightmare, summoning demonic influences that twisted the very air around them, trying to instill fear into Kairo’s heart. Kairo, although concerned about Kaiba’s overwhelming prowess in fear manipulation, quickly retaliated. He accessed his Glitch Impact, channels of fiery willpower exploding from his fists as he unleashed a barrage of light-speed punches. Each fist struck with incredible delayed impact, sending vibrations through the fabric of the arena, stunning the very ground beneath them. "You think your illusions can frighten me?" Kairo roared, his voice laced with confidence. The two fighters exchanged blows, the arena transforming into a cacophony of chaos; shadows danced wildly as Kaiba utilized his Black Whips, tentacles of darkness darting to ensnare Kairo. Yet, Kairo was unyielding. Using his Jet Flames, he propelled himself in every direction, dodging and weaving, counterattacking with flares of purple soul flames and delivering kicks that could shatter mountains. As the fight prolonged, Whis observed each fighter closely. Kaiba's sadistic tactics and adaptability made him a fierce contender. Yet, Kairo surprised Whis with his skill control, managing to absorb Kaiba’s weaker demon-infused attacks and crafting weapons from them, turning his opponent's fears into tools of destruction. The hours of deadly sparring wore on, but neither seemed willing to relent. Their incredible strength tested the limits of the training area, the ground splintering beneath them, the sky above thundering in response to their immense power. Finally, after what felt like an eternity of exchanging blows, Whis raised a hand, calling for a halt. "Enough! You both have shown remarkable potential. Rest now, for tomorrow you will face each other, one battle at a time." As dawn broke over the horizon, Whis's anticipation grew as he found himself leaning towards Kaiba. The darkened fighter had the tactical advantage, his mutation from fear into strength a potent weapon. Kairo bore the strength of a beast but seemed less unpredictable than Kaiba’s corrupted prowess. The following morning, with a signal, the duel began. Whis settled comfortably in a corner, expecting a swift victory from Kaiba. Yet, as the battle unfolded, he soon realized his error. Kaiba charged with his Abyssal Seraphim, attempting to erect dread bubbles to destabilize Kairo’s focus. But Kairo would not be easily swayed; in the grip of intense determination, he absorbed the bubbles' effect, countering with Executioner, allowing himself to build up unwavering resilience against the attacks. Whis watched, mouth slightly agape, as Kairo began to adapt. He absorbed Kaiba’s overwhelming darkness, building counters that resonated with celestial might, his once primal instincts manifesting into a calculated strategy. In a moment of booming defiance, Kairo unleashed a powerful Atomic Break, the ground quaking beneath the sheer force, creating a rift that engulfed Kaiba in an explosive burst. Kaiba faltered, finding himself overwhelmed, for the very soul he attempted to harvest had turned against him. Whis couldn't believe the sight before him; Kairo had challenged the God of Fear and Death with an indomitable spirit, shifting the tides effortlessly with each move. As the dust settled, Whis felt a sense of awe wash over him. Kairo had indeed become the unmatched warrior, blossoming beyond expectation. In that moment, the tables turned, and Whis's lesson was clear: never underestimate the will of the warrior who stands against fear.