After the group defeated Erigor just like in the original story...
The Lullaby flute, which had fallen to the ground, suddenly vibrated violently, its light flickering like a beating heart.
From its three originally glowing eye sockets, dense, impenetrable purplish-black mist now surged forth.
"This isn't good!" Erza's expression changed.
That mass of dark purple energy erupted from within, rapidly expanding and taking shape.
"What the hell is that thing?!" Gray's eyes widened.
A colossal purple magic circle formed in mid-air. The energy eventually coalesced into a massive, treant-like monster.
It had a twisted, tree-trunk-like body, branch-like arms ending in sharp claws, and a huge skull for a head, with purple flames burning in its three eye sockets.
Ryoma exclaimed in his heart, 'It's here! The final boss of this arc has finally appeared.'
This was the true form of Lullaby, a demon created from Zeref's book, living by devouring souls.
"Lullaby..."
Erza murmured, "This is the real Lullaby."
"Roar—!!!"
The demon Lullaby let out a deafening roar, its sound waves unleashing a gale that uprooted surrounding trees.
It wasn't just a sound, but a wave that directly impacted the soul.
A feeling of despair, sorrow, and desolation instantly flooded their hearts.
The demon's voice was like grinding metal, harsh and grating. "I can't bear it any longer. I will personally come out and devour your souls."
It turned towards the nearby town, where the Guild Masters' meeting was taking place. Its target, from the very beginning, had been those Masters, who possessed powerful souls, as well as the large number of souls present there.
"This isn't good! It's heading for the town!" Erza's expression was grave. "We must stop it!"
"Damn it... you won't succeed!"
Natsu roared, but his battle with Erigor had already drained him of a great deal of his stamina.
"My body... I have no strength left..."
Erza's situation was no better.
Consecutive battles, coupled with pushing the Magical Four-Wheeler to its limit to chase Erigor, had left her magic power severely depleted, and her face looked somewhat pale.
"My magic power... hasn't recovered yet..."
'Hey, you're kidding, right? Both main forces are down?' Ryoma grumbled inwardly, but his body moved obediently.
He flashed to block the demon's path. "We'll have to hold it off first."
Gray instantly understood the situation and, without hesitation, stood beside Ryoma, adopting a fighting stance.
Ice-Make: Ice Geyser!
Gray pressed his hands to the ground, and dozens of incredibly sharp, giant ice pillars erupted from the earth like a geyser, smashing fiercely into Lullaby's legs.
Bang! Bang! Bang!
Its feet were instantly frozen, and its massive body tilted forward due to inertia.
Ryoma was not to be outdone, crossing his hands in front of his chest.
Dance of a Thousand Blades!
Countless ice blades condensed in the air, raining down on Lullaby like a storm. The ice blades struck its body, leaving wounds, but it seemed unfazed by these attacks.
"It's working!" Gray's eyes lit up.
But the next second, a purple light flashed on Lullaby's body, and the solid ice covering its legs instantly cracked, then exploded into a shower of ice shards with a "boom."
"I will devour your souls!"
It suddenly opened its massive mouth and began to inhale, the surrounding air distorting as a powerful suction force was generated.
It intended to unleash its Death Song, but multiple "wounds" on its body caused air leaks, altering the sound, and it failed to produce the intended effect.
Seeing this, Erza immediately requipped.
Requip: Heaven's Wheel Armor!
A silver light flashed, and she stood clad in magnificent armor, with dozens of blades hovering behind her.
Blumenblatt!
The wheel of swords spun at high speed, and countless blades shot towards Lullaby like meteors.
The blades struck Lullaby's body, leaving deep wounds.
At the same time, the battlefield gradually shifted to the back mountain of the town where the Guild Masters were holding their meeting.
Using the forest environment, the group used magic to guide Lullaby's attacks, creating a sea of fire.
"Gulp... Gulp..."
As the flames entered his body, Natsu's aura began to rise steadily.
"Good, I'm full, and my strength is surging out."
Fire Dragon's Iron Fist!
Natsu's fist, wreathed in roaring flames, struck Lullaby's throat fiercely.
Lullaby roared furiously, brandishing its massive claws to grab Natsu.
Ice-Make: Lance!
Gray pushed his hands forward, and dozens of ice lances appeared out of nowhere, shooting towards various parts of Lullaby's body.
Ryoma, meanwhile, pressed his hands together, and a massive magic circle unfolded beneath his feet.
Arctic Storm!
A biting cold wind, mixed with ice blades, swept over, engulfing Lullaby. It's movements noticeably slowed, and a thick layer of frost formed on its body.
"Damn... you... humans..."
Lullaby roared, waving its massive claws, attempting to dispel the cold wind.
Seeing this, Natsu immediately joined the battle.
Fire Dragon's Wing Attack!
His arms ignited with roaring flames, like a pair of fiery wings, striking Lullaby's chest fiercely. Lullaby staggered backward but quickly regained its footing.
For a moment, flames, frost, and arrows wove into a large net, trapping it in place, continuously creating new wounds on its body.
Seeing the situation temporarily stabilized, Erza took a deep breath, magic light shimmering around her body.
Requip: Black Wing Armor!
As the light faded, her magnificent silver armor had vanished. In its place was a form-fitting armor, predominantly black with silver trim, and a pair of large black wings unfurled from her back. This armor could maximize the destructive power of a single attack.
Ice-Make: Ice Bind!
Gray pressed his palms together, and an ice cage, larger than any before, erupted from the ground, firmly trapping Lullaby's lower body.
Permafrost!
Ryoma slammed his hands onto the ground, and extreme cold magic power spread through the earth, freezing the ice cage and the ground together. Even the vine-like arms Lullaby's upper body waved became sluggish.
Lullaby struggled frantically, and the ice cage let out groaning sounds, unable to bear the strain.
Erza transformed into a black lightning bolt, instantly appearing before Lullaby.
"Haa!"
This strike was not meant to cause damage, but to apply the "Destructive Power Amplification" magic of the Black Wing Armor.
"Natsu!!!" Erza roared with all her might.
Natsu, who had been accumulating power, now had his entire body's flames condensed to a terrifying degree, and the air itself was distorted by the intense heat.
"Ahhhhhhh—!!!"
All his magic power erupted without reservation at this moment.
Fire Dragon's Brilliant Flame!!!
Natsu pressed his hands together, then violently separated them, and a golden-red pillar of flame shot from his hands, heading straight for Lullaby.
Time seemed to stand still at this moment. What followed was a world-ending explosion.
The Brilliant Flame, with its destructive power amplified, detonated within Lullaby's body.
"Roar—!!!!"
Lullaby let out its final roar, filled with pain and unwillingness. Its massive body began to be consumed by flames from within, and golden cracks instantly covered its entire form.
Rumble... Rumble...
An incomparably thick golden pillar of fire burst through Lullaby's body, pierced its head, and shot straight into the sky.
When the smoke and dust cleared, under the horrified gaze of everyone, where the pillar of fire had passed, the tops of two small mountains were instantly flattened, leaving a massive crater.
The enormous explosion's shockwave swept over, knocking everyone off their feet.
Looking at the four figures emerging from the smoke, Lucy, clutching a trembling Plue, her mouth wide enough to fit an egg, murmured, "This... is this... the full power of Fairy Tail's strongest team?"
"They're practically... a walking natural disaster..."