Starting with No Game No Life: Infinite Chests

"Well then, let's continue this battle," Riku said with a gleam of excitement, his gaze sharpening as Sirzechs unleashed world-shattering demonic power.

With those words, Riku activated [Heavenly Shift] and vanished, appearing instantly in front of Sirzechs and throwing a punch imbued with terrifying force.

"Boom——!"

Sirzechs's expression turned serious. A dark crimson magic circle appeared in front of him, intercepting Riku's blow. The heavy sound echoed as Sirzechs was sent flying back.

But unlike other powerful foes, Sirzechs wasn't left in a sorry state; he merely slid back a short distance before stabilising himself. Riku's violent punch, landing on Sirzechs's magic circle, only left a few cracks.

Sirzechs had defended against Riku's attack!

This sight made Serafall and the others feel a surge of hope. After all, Riku's previous display defeating every other Maou-class powerhouse with a single punch was simply too overwhelming.

Riku glanced at the traces of Power of Destruction still clinging to his fist, shaking them off effortlessly.

"So you wove Power of Destruction into your magic circle and used it to annihilate my punch's force. No wonder you could withstand it," he commented with a smile, offering rare praise. Even with Sirzechs unleashing his full power, it was unthinkable for anyone to easily block an attack from Riku, whose raw strength was enough to overpower even a Heavenly Dragon. But this method, using the Power of Destruction, was effective. While it had its limits, it was enough to erase most of Riku's force. The rest, Sirzechs could handle with his defences.

"This fight is turning out to be even harder than I imagined," Sirzechs admitted, more solemn than ever.

"But I have my own reasons for not backing down," he murmured, spreading his palm wide.

In an instant, deep crimson destructive power coalesced into countless serpent-like forms, rushing at Riku and filling the air with ruinous energy, so intense it destabilised the very fabric of space.

"Sssshhhh——!"

Riku's response was simple and brutal: he barreled straight through the assault, smashing the dark red serpents into motes of light. The destructive aura did wear away at the defensive aura surrounding him, but Riku's regeneration outpaced the destruction.

As Riku was about to reach Sirzechs, Sirzechs's eyes flashed, summoning a vast amount of power; the magic circle on his palm gleamed ominously.

"Boom——!"

Suddenly, the dark red motes that Riku had shattered, as well as the snakes swirling around him, exploded violently, shaking the very heavens and earth. Distant cities trembled, buildings collapsing under the shockwave.

Jibril, Schwi, and the others watching the battle immediately raised their defences. For Grayfia and the devils present, especially those wounded, it took everything they had to protect themselves. The weaker ones scrambled to escape the area, battered and covered in dust.

"That last move was pretty good. I have to give you some credit," Riku said as he shot out of the explosion zone, suddenly appearing above Sirzechs with a sly grin. "So, I'll reward you with a real punch."

Sirzechs's expression changed. Without hesitation, he conjured layer after layer of defensive magic circles. If Riku was a brawler, then Sirzechs was the mage no mage ever wanted to be caught in melee range by a warrior.

"Hirudora!!"

As Sirzechs defended, Riku unleashed his next attack. Instantly, a gigantic tiger formed from the Power of Destruction leapt forth, smashing into Sirzechs with unstoppable might.

"Crack——!"

There was no time to be shocked that Riku could wield the Power of Destruction; the shields Sirzechs had so painstakingly erected were shattered layer by layer. Sirzechs himself was sent crashing from the sky, plummeting down like a meteor; only the last layer of his defences remained, now riddled with cracks.

Sirzechs's face paled as he desperately tried to reinforce his defences. The clash of Power of Destruction against Power of Destruction was brutal, even if Sirzechs's own power was purer, he could no longer obliterate Riku's attacks as easily as before.

"Boom——!"

In less than a split second, Sirzechs was slammed into the ground, smashing open a second massive crater. The earth trembled, fissures spreading out from the impact; where the destructive energy touched, the earth was erased on a molecular level—as if some monstrous force had taken a huge bite out of the land.

And Sirzechs? He lay deep within the earth, his condition unknown.

"——!"

Serafall and the devils stared, eyes wide, shocked to their core.

Sirzechs, the legendary Super Devil, had unleashed truly monstrous power. Yet, he was still being completely overpowered by this man. This was simply too absurd!

"Why can he use Power of Destruction?!" Grayfia, ever the serious and detail-oriented one, was shaken, but more than that, she was puzzled by this crucial detail.

The Power of Destruction is the symbol of the Bael clan, first among the 72 Pillars. Only those of the Bael bloodline, or children of the Bael-Gremory union like Sirzechs and Rias, can use it. Among the younger generation of Bael, not even all of them have awakened it. There are barely enough people in the whole world who can use it to count on one hand.

Yet this outsider, Riku, could wield the Power of Destruction and seemingly to an extreme degree. It was simply unbelievable.

"Not bad at all," Schwi remarked, a faint glimmer of data running through her eyes. She lightly raised her pure white finger, and a small swirl of crimson destructive power appeared. She muttered to herself, analysing its structure.

If Grayfia and the devils could see this, they'd probably question reality, no, their very existence. In just a moment, thanks to Riku and Schwi, what was supposed to be one of the rarest abilities among devils was suddenly everywhere…

"This level of damage won't kill you. So you might as well come back out," Riku said nonchalantly, floating in the sky and looking down at the dust-choked battlefield.

"…You make it sound so easy," Sirzechs coughed, dragging himself out of the massive crater a few seconds later, his face pale as he looked up at Riku. The aura of destruction around him was now even more unstable, dangerously so. If he lost control, he'd destroy not only himself, but everything nearby. This Destruction Mode granted Sirzechs Transcendent power, but it was a double-edged sword.

The fluctuations in Sirzechs's aura made Serafall, Grayfia, and all the devils present sink into despair. Sometimes, the birth of hope only means a greater fall into despair.

"Can you tell me how you're able to use Power of Destruction?" Sirzechs asked, shaking his head and giving a wry smile.

"I learned from you," Riku replied calmly, glancing at Sirzechs. With the source of chaos energy, as long as he assimilated a given power, he could create or convert it at will. Converting ordinary demonic energy was trivial. Even a special and rare energy like the Power of Destruction, after fighting Sirzechs for so long, could be replicated and transformed just as easily.

"…You learned it from me?" Riku's offhand reply left Sirzechs, Serafall, and all the devils looking dumbfounded.

Seriously? The Power of Destruction is a bloodline inheritance. How can you just "learn" it?

"Anyway, I'm starting to get bored with this fight. If we keep dragging it out, things could get dangerous, so I'll just end it now," Riku said abruptly.

Sirzechs's heart clenched at those words, and he desperately tried to stabilise his rampaging power.

In that moment, Riku's right hand was suddenly covered in a crimson gauntlet, leaving Sirzechs, Serafall, Grayfia, Tannin, and all the other powerhouses present staring in shock.

"The Boosted Gear?! You're the current Red Dragon Emperor?!" Sirzechs's pupils contracted, his voice tense.

"The Red Dragon Emperor, huh? Well, mine is a little different. But whatever think what you think," Riku said with a small shrug. His gauntlet was purer than the Sacred Gear of this world, lacking any "curse," and its potential was far greater.

"Balance Breaker." As the others puzzled over Riku's words, he spoke quietly.

The green jewel embedded in the gauntlet flashed, then crimson light enveloped Riku.

"Not good!" Sirzechs felt powerless to stop what was happening.

A second later, Riku appeared before them clad in an aura of regal, blood-red armour. The sheer pressure of his presence soared to an unthinkable level, casting the entire Underworld beneath a draconic might so fierce that the land itself seemed to cry out, the sky quaking, all of the Underworld trembling.

Every being in the Underworld felt suffocated beneath the oppressive aura.

Those closest Sirzechs, Serafall, and the other powerhouses could only stare in awe and terror.

"Is this really the Boosted Gear?" Sirzechs and the rest were shaken, both astonished and deeply doubtful.

This Balance Breaker was unlike anything they'd ever seen, far more stylish, and the draconic aura was much purer, without a trace of the curse they knew so well.

And even though a Sacred Gear could grant power to slay gods and Maou, if its wielder was already stronger than Maou-class, stronger even than a Heavenly Dragon, could the so-called Balance Breaker really offer such a huge increase? Could a Balance Breaker be amplified so much?

In the face of Riku's overwhelming power, Sirzechs simply fell silent. Riku was just too mysterious, powerful, enigmatic, and clearly holding back other trump cards. Was the Underworld really capable of resisting someone like this?

Seeing Sirzechs's fighting spirit fade, Riku's own interest faded as well.

"Looks like you're out of will to fight. In that case, it's time to bring this battle to a close." Riku's tone was as calm as ever.

"…Heh," Sirzechs gave a helpless laugh, his eyes sharpening with one last glimmer of pride. Though Riku's power far surpassed his own, he was still a Maou; he wouldn't yield to anyone's strength.

"That's more like it," Riku nodded approvingly.

"Boom——!"

No one saw how Riku vanished and reappeared before Sirzechs, only that, a split-second later, Sirzechs was sent flying, the defensive barrier of destruction magic around him shattering as he spewed blood and crashed to the ground like a meteor, shaking the land.

But this time, Sirzechs had no strength left to rise. He could only gaze up at the Underworld's purple sky, his Power of Destruction fading, his body reverting to its normal state.

Defeat total, crushing defeat.

"Sirzechs… lost…" Serafall, Grayfia, and the rest did not blame Sirzechs for his loss. They just stood in silent shock. It wasn't that Sirzechs was weak; he was incredibly strong, but his opponent was simply in a league beyond them all.

In their understanding, only beings like Ophis or the Great Red stood at such an unreachable height.

Now, there was another…

Where on earth had this monster come from?

Serafall smiled bitterly. How laughable that they'd initially thought he was just a peak Maou-class fighter…

"Sorry, all you Maou and nobles, consider yourselves captured." Riku hovered in the air, gazing down at the battered, defeated devils, a faint smile on his lips as he made his declaration.

"..." The devils could only bow their heads in defeat.

"…Although, it looks like we have more guests coming," Riku added, glancing at a point near Sirzechs with an amused look.

The devils were momentarily stunned. Jibril and Schwi, who had been moving to Riku's side, also paused.