"Cero."
The crimson beam erupted from Grimmjow's palm with the roar of a jet engine. It approached the hoard and the lesser demons who couldn't get out the way in time as it carved a trench through the cavern floor, vaporizing twenty lesser Oni instantly before slamming into a pillar, collapsing the ceiling in a shower of stone and dust.
Grimmjow didn't wait for the debris to settle as he immediately moved again with the chaotic grace of a predator, his Sonido leaving flickering blue afterimages in the stagnant air turning him into nothing but a blue blur and a whirlwind of violence. He caught a Red General by the throat, hoisting it up just as three High Oni unleashed a combined volley of violet lightning and searing plasma at him.
"Thanks for the shield, pal!" Grimmjow cackled, holding the thrashing General in front of him. The General's massive body absorbed the brunt of the assault, its armor melting and sizzling against its skin as it fused with it due to the high temperature, before Grimmjow shoved the twitching carcass into the attackers, knocking them back like bowling pins.
"Is that it?" Grimmjow taunted as his voice echoed through the chamber, "I'm barely breaking a sweat. If this is the best this pathetic gate can offer, you should just pack it up and go home."
He vanished in a sudden burst of sonido leaving a static boom in his wake, reappearing mid-air above an invisible Oni that had tried to flank him. He didn't even look down as he simply drove his hand straight through its chest, his fingers acting like a serrated spear and ripped upward, bisecting the demon from groin to skull in a spray of purple gore.
Minoru and his team watched from the floor, paralyzed. They were witnessing a massacre here. Grimmjow danced between the blows of the generals and high Onis, his feral smile never leaving his face as he tore through the hundreds of lesser monsters with his bare hands, using pillars as launchpads. Every time he landed, the floor shattered.
He caught a High Oni's strike, then spun and jammed his palm against the demon's sternum, "Cero."
The blast detonated against its body, blowing the High Oni's torso into atoms and punching a hole through the dungeon wall that opened into the hallway outside.
Grimmjow didn't stop at that, he vaulted into the air, hovering momentarily, his blue hair lashing in the pressure of his own Reiatsu. He then finally drew his katana, Pantera, its blade rasping against the scabbard with a sound like a guillotine.
"You're all so boring," he sneered, looking down at the remaining three Generals and the scattered four High Oni. He then descended like a meteor with his sword cleaving through a General's armored neck with a wet thwack. He spun with his boot catching a High Oni in the jaw, launching it through the roof of the chamber.
To those who were watching him fight it as if he was everywhere at once. One moment he was severing limbs, the next he was pinning a General to the wall with his bare hand and driving his knee into its gut until its spine snapped.
"Come on! Entertain me!" he roared, blood spraying across his white jacket. He looked over his shoulder at the paralyzed raid team as his eyes glowing with sadistic mirth. "What's the matter? You guys look like you've seen a ghost. Don't worry, the 'fun' part is just getting started."
He suddenly slashed horizontally, the arc of his blade releasing a shockwave that erased the remaining lesser Oni in the immediate vicinity. At this point, moment and time, he was the undisputed master of this room, a king of carnage, turning the deadly raid into a one-sided dance of death.
"Only two Generals left and three high oni" he hummed, flicking blood off his blade with a lazy, elegant motion. "Who's next?"
———————-
The chamber had turned into a canvas of gore, and Grimmjow was painting with everything he had.
When the two remaining Generals and others lunged in a coordinated pincer, he Sonido-ed into the center of the formation, his speed was so absolute that the air around him shrieked. He caught the first General by the horn, swinging its massive body like a ragdoll into the second, the collision shattering both of their armored chests into shrapnel.
"You're too slow," Grimmjow hissed.
The remaining high oni bellowed, their skin glowing with a violent, violet mana-surge as they swung their colossal axes. Grimmjow didn't bother dodging and simply lanted his feet, the floorboards beneath him disintegrating into dust, and caught the blades with his bare hands. The force of the strike was enough to collapse the surrounding pillars, sending tons of masonry raining down, but Grimmjow stood immovable.
"My turn."
He simply shoved them back with his raw physical strength that far exceeded the structural integrity of the monsters. He pushed their weapons back into their own faces, the iron-wrought blades biting deep into their skulls. As they reeled, he hopped onto the shoulders of the nearest oni.
"Peek-a-boo."
He then drove his fist into the Oni's spine and released a concentrated blast of Reiryoku which exploded outward. The Oni's body imploded from the inside out, turning into a fountain of black sludge. The rest of the Oni's roared as panic finally broke through its tactical calm, and tried to retreat but Grimmjow vanished, reappearing directly above it.
He drew Pantera halfway just enough to let the blade hiss. The flash of steel was a silver arc of death. In one fluid motion, he dismantled the General, severing its limbs with such precision that the creature didn't even realize it was dead until the pieces began to slide apart.
But he wasn't done. The remaining horde of lesser Oni that had stopped attacking due to self preservation, seeing their champions fall, wailed in terror and tried to scramble toward the dungeon exits.
"Oh, no," Grimmjow grinned, "You're not going anywhere."
He soared into the air, hovering thirty feet above the ground, his blue hair lashing in the gale of his own spiritual pressure. He looked down with a feral glint in his eyes. He spread his arms wide, his palms facing the fleeing masses.
"I'm just getting started!"
He pointed his palm downward. A massive, swirling vortex of red energy began to condense, humming with a frequency that made the very air liquefy. The raid team, cowering in the corner, watched in sheer, unadulterated horror as the orb grew to the size of a carriage then shrank and turned blue.
"Gran Rey Cero."
The blast was what one would call a literal tidal wave of annihilation. It descended like a falling sun, obliterating the entire southern half of the chamber and when the light finally faded, the wall was gone, the floor was a molten crater, and the hundreds of Oni had been scrubbed from existence.
Grimmjow landed amidst the silence, his boots crunching on the ash of his victims. He sheathed his sword, the metallic click sounding like a death knell in the quiet room. He turned his head, his gaze settling on the shattered raid team, his face twisted in a look of profound, arrogant amusement.
"Well," he breathed, steam rising from his skin. "That's the trash cleared out. Now... let's see how the 'bosses' are holding up shall we."