The Corrupted Core Guardian moved first.
It did not charge like the beasts before it, nor did it hesitate like a creature bound by instinct. It stepped forward with deliberate weight, each movement synchronized with the violent pulse of the corrupted core behind it.
The entire chamber reacted.
Metal groaned. Pipes rattled. The air thickened as if the tunnel itself was breathing.
Cassian felt it immediately.
This wasn't just a boss.
It was anchored.
The Guardian raised one massive arm and brought it down.
Aurora met it head-on.
The impact thundered through the chamber as her fist collided with its descending strike. The ground beneath her cracked, and for a moment, the two forces locked against each other.
Then she slid back.
Boots scraping against concrete, she exhaled sharply and reset her stance.
"Yeah," she muttered. "That's different."
The Guardian didn't pause. Its second arm lashed out, faster than something that size should have been able to move.
Aurora twisted aside, but the strike clipped her shoulder and sent her skidding across the floor.
Cassian stepped forward.
[Mana Construct Activated]
The ground beneath the Guardian surged upward in a layered formation, attempting to disrupt its balance.
[Mana Consumed: 26]
The construct hit.
And failed.
The Guardian didn't stumble.
Instead, the metal fused along its legs pulsed, absorbing part of the impact as if the environment itself reinforced it.
Cassian's eyes narrowed.
"Elara."
She was already moving.
"I see it."
Her hands lifted, fingers weaving precise patterns in the air. Thin streams of controlled mana extended toward the Guardian—not to strike, but to trace.
To read.
The Guardian roared.
The sound reverberated through the tunnel, distorting the mana currents around them. Then it charged.
Not at Aurora.
At Cassian.
He didn't move.
[Mana Construct: Reinforced Barrier]
Layers of blue energy formed instantly in front of him.
[Mana Consumed: 34]
The Guardian's fist collided with the barrier.
The first layer shattered.
The second cracked.
The third held—barely.
The force drove Cassian back several steps, pressure slamming into his core like a physical weight.
[Mana: 61 / 165]
Aurora re-entered the fight.
She came from the side, her movement explosive. Her fist drove into the Guardian's exposed flank, this time targeting the joint between its armor plates.
The impact landed clean.
A crack spread across the metal.
The Guardian reacted immediately.
Its arm twisted unnaturally, striking backward.
Aurora blocked, but the force still threw her off balance.
"Harder than it looks," she said, landing lightly and circling.
Cassian exhaled slowly.
Something wasn't right.
They were landing hits.
Real hits.
But the Guardian wasn't weakening.
It wasn't slowing.
It wasn't even adjusting defensively.
It was enduring.
He extended his senses again—past the Guardian, deeper.
To the core.
And there it was.
A constant stream of energy flowing from the corrupted core directly into the Guardian's body.
Not passive.
Active reinforcement.
"Stop attacking it directly," Cassian said.
Aurora glanced at him mid-movement.
"You got a better idea?"
"Yes."
Elara's voice cut in, precise and calm.
"It's being sustained."
Cassian nodded once.
"Linked to the core."
The Guardian charged again, forcing them to move.
Aurora intercepted, drawing its focus while Cassian shifted position.
Elara extended her mana threads further, mapping the energy flow between the core and the Guardian.
"The connection points are embedded along its spine and chest," she said. "Multiple anchors."
Cassian processed instantly.
"That's why damage isn't sticking."
Aurora ducked under another strike and countered with a sharp upward blow that snapped the Guardian's head back slightly.
"Then we break the connection."
Cassian shook his head.
"Not by force."
He stepped forward again, raising both hands this time.
[Mana Construct: Structural Grid]
The chamber floor lit up in a far more complex pattern than before.
[Mana Consumed: 42]
Lines of energy extended outward—not just beneath the Guardian, but toward the corrupted core itself.
The Guardian reacted.
For the first time, it hesitated.
Then it roared.
The core behind it flared violently.
The entire chamber shook.
Aurora's expression sharpened.
"It didn't like that."
"No," Cassian said calmly. "It understood it."
The Guardian shifted its behavior.
It stopped focusing on them.
And turned toward the environment.
Its arm slammed into the tunnel wall.
Concrete exploded outward.
Support beams snapped.
The ceiling above groaned ominously.
Elara's eyes widened slightly.
"It's destabilizing the chamber."
Aurora looked up briefly.
"Trying to bring the whole place down?"
Cassian adjusted the construct instantly.
"It's trying to interrupt the grid."
Another strike.
More structural damage.
Chunks of debris fell from above.
The battlefield was changing.
Fast.
Aurora moved again, this time targeting the Guardian's legs to limit its movement.
"Keep it busy," Cassian said.
She smirked slightly.
"On it."
Elara shifted her position closer to Cassian.
"If the chamber collapses, the core destabilizes with it."
Cassian's focus sharpened.
"Then we don't let it collapse."
He extended the grid further.
Not just around the Guardian.
Around the entire chamber.
[Mana Consumption Increasing…]
Pressure built in his core.
His control stretched thin.
But the structure held.
For now.
The Guardian roared again and turned back toward Cassian, recognizing the real threat.
It charged.
Faster than before.
Cassian didn't move.
He couldn't.
The grid required full focus.
Aurora intercepted.
She met the Guardian head-on again, but this time her strike wasn't about overpowering it.
It was about timing.
She drove her fist into the cracked joint from earlier.
The damage deepened.
The Guardian staggered—just slightly.
Elara seized the moment.
Her mana threads locked onto the exposed connection point along its spine.
"Now," she said.
Cassian's eyes sharpened.
He shifted the grid.
Redirected it.
Focused it.
[Mana Construct Reconfigured]
The lines of energy converged toward the Guardian's back.
Targeting the connection.
The core pulsed violently in response.
The Guardian roared.
The chamber shook again.
But this time—
The connection flickered.
Just for a second.
Cassian felt it.
A weakness.
Not enough to break.
But enough to prove one thing.
This fight wasn't about destroying the Guardian.
It was about severing it.
He exhaled slowly.
"We're not killing it," he said.
Aurora glanced at him, breath steady despite the pressure.
"Then what are we doing?"
Cassian's gaze locked onto the glowing core behind the Guardian.
"We're cutting it off."
Elara nodded immediately.
"That will destabilize both."
Aurora's grin returned.
"Good."
She rolled her shoulders.
"Because this thing is getting annoying."
The Guardian charged again.
But this time, Cassian was ready.
The next phase of the fight had begun.