True Power

The 0th form. A magic technique that took advantage of his knowledge of the demon slayer forms and allowed him to fully embody whatever magical attribute he was using. In a way, it was his own version of [Ultimate Magic] but made solely for himself. In this instant, he was fully embodying the true essence of [Breath of the Beast].

Roaring out at the top of his lungs, he stripped away Lucifero's [Gravity Magic].

If he had to describe the difference between the 0th form and the other [Breath of the Beast] forms. He would say that the previous forms only allowed him to rip and tear apart his opponents. Now he was no longer limited to just ripping them apart! He could devour them. And just like Secre had guessed, with his ability to devour damage he was currently invincible.

But that wasn't even half of it. This form allowed him to do so much more. With his devouring ability, he no longer needed to eat, drink or sleep. Mana itself would sustain him. He could fight endlessly and forever.

'What a monster...'

Sucking in a deep breath, Nacht watched the battle from a distance. Not even taking his time to blink, his breathing was shallow and unsteady. From his point of view, Grim was getting further and further away from being human. Vertical pupils? Sharpened teeth? Facial markings? It was like he was looking at a devil that was not a devil.

And the way he fought... He reminded him of the twin devils.

All Burning.

All Freezing.

All Devouring.

In this world, in order to unleash their true power, Devils needed access to a grimoire. Zagred was a great example of this. Without one, the spells they could use would be heavily limited. But this form of Grim's... it allowed him to abandon his grimoire. He no longer needed to use spells, he had become the spell itself.

****

Back at the battlefield.

"You move when I say you can move!"

-BAANG!

"You'll bleed when I tell you to bleed!"

-BAANG!

"And you'll die when I tell you to DIE!"

-BAAAANG!!

Shaking the sky and cracking the earth, Grim's knuckles throbbed as he hit Lucifero with a heavy 3 piece combo.

*PAH!*

Spitting out a mouthful of dark blood, the look in Lucifero's eyes had long since surpassed the stages of rage.

'DAMMIT!!!!!!!!!!!!'

-BOOOM!!

Surging with limitless mana, he threw a punch forward.

"COME!" Grim welcomed him not backing down in the slightest. Instantly devouring the mana around him, he replenished his lost mana reserves and threw a punch of his own.

*BAAAANG!!!*

It was truly was fight between those who possessed an Infinite supply of mana and a Limitless amount mana.

-Craaack

The moment the two fists collided, the space around them ruptured and collapsed.

"GRIM!!" Everyone shouted in panic seeing glass-like cracks appear in the air.

""ARRRGHHHHH!!!"" The two roared clenching their smashed fists and driving them forwards.

*BOOOM!* *BOOOM!* *BOOOM!*

Not willing to give an inch, the endless scores of mana pouring out of their bodies made the world around them cry out as space continued to fold and unfold itself without any sign of stopping. With the crazy amount of mana the two were outputting, getting close to them was suicidal. Just the mana waves created from the collision of Grim's devouring ability and Lucifero's gravity magic alone threatened to atomize everything. If it wasn't for Grim constantly devouring the rampaging energy, it was hard to say if Asta and the others could have survived this.

"Incredible." Mereoleona muttered unable to calm her beating heart.

Such Strength... Such Power... It was truly out of this world.

Watching Grim fighting, she couldn't even imagine what he did to attain this power.

He didn't even need to dodge anymore! And that monstrous physical strength, although it wasn't completely on par with Lucifero and his arms broke whenever the two clashed. The fact that Lucifero wasn't able to completely overpower him spoke volumes.

'I still have a long way to go.' She grinned clenching her fists. 'I'll catch up to you soon! Just you wait!'

"That's Grim's true power..."

"I knew it, Demon Slaying magic... It's something else."

Having just had their wounds taken care of, Asta and chibi Liebe could only watch on helplessly as memories of their defeat at the hands of Lucifero replayed in their heads.

'Dammit!' They cursed and clenched their teeth in frustration. 'Are we really that weak!?'

[Devil Union], it couldn't do a damn thing! Once again, they had to leave everything to Grim. They were nothing more than a goddamn burden! They couldn't even get close enough to help! What was the point of all their training if they were just here to sit on the sidelines!

Dammit! Dammit!! Dammit!!!

For Liebe who had spent most of his life inside Asta's grimoire cursing Lucifero and all of devil kind. This hit him especially hard.

"Why, WHY AM I STILL NOT STRONG ENOUGH!!"

"Liebe..."

For Lucifero to be right in front of him and he's still unable to avenge Licita. What kind of cruel joke was this?

"Its my fault *sniff* If I had magic... If she had never met me... If I hadn't left the underworld... She wouldn't have died. SHE'D STILL BE ALIVE TODAY!"

"I HATE HIM!" He clenched his fists and punched the floor as tears rolled down the side of his face. "I HATE HIM SO GODDAMN MUCH!!"

"Liebe..." Asta's heart hurt to see him like this.

"But more than anything *sob* I hate myself."

Hanging his head and unable to stop the tears from flowing, all of Liebe's sadness and regret caused his memories and thoughts of Licita to pour into Asta. All of the love and warmth he experienced with Lictia as well as the despair he felt when he lost her, Asta saw it all.

***

"GIVE UP! YOU'LL NEVER DEFEAT ME YOU INSOLENT WORM!"

"YEAH? JUST WATCH ME YOU WRINKLED SON OF A BITCH!!"

Enhancing his speed with gravity and using his new ability to devour air resistance. The two clashed a dozen more times. Fighting at a speed that even the spectators found hard to follow, the two started teleporting around the battlefield with every breath.

Honestly, the entire thing felt ridiculous. These were two of the strongest magic users in the world and they were fighting like common thugs. If not for the fact that the two were teleporting, people would forget that they were even using magic. No spells, no tactics, no tricks, just straight hands.

Watching this as a spatial mage, Finral felt like he was on the brink of a breakdown. Why did the instanteous teleportation spell that took him months to learn suddenly feel so cheap?

Since when was teleportation so easy?

Sensing his internal struggle, Yami put a hand on his shoulder.

"Captain?"

Shaking his head, he gave Finral some words of comfort.

"Don't compare yourself to those two. They're literal monsters."

"Captain~" He felt touched.

Unfortunately the look on Yami's face was anything but touching.

"Now do me a favor and prepare to open a portal to the Black Bulls bathroom. I haven't taken a dump in a week and I feel it coming!"

"..."

-BOOOM!!

With each clash the intensity of the mana waves around them grew more destructive and caused visible sparks of mana to start appearing. No longer able to withstand their clashing powers, reality shattered around them.

"GRIMM!!" The Clover pack screamed seeing the shattered shards of reality suck him and Lucifero into an unknown space.

-BOOM!!

-BOOM!!

-BOOM!!

Fighting in the unknown space without slowing down, the full power of Grim and Lucifero reached its peak as Lucifero kicked Grim so hard that blood shot through the gaps in his teeth and he was kicked out of the unknown space.

'He exceeded the damage I could devour!'

Seeing this, Lucifero became relentless. Attacking him with swift and heavy kicks, he felt like he could finally see light at the end of the tunnel.

In response to this, Grim summoned out his Beast Swords and the two continued their battle across an unfamiliar looking Kingdom.