Death Bastion turned into a vise that ground skeletons into dust and zombies into meat paste. After losing their infantry, the Ghouls stopped the attack and retreated. The barrier prevented them from sneaking inside the camp from below just like the sun made attacking from above suicidal.

"This is all your fault!" Captain Kortus said before people could have a clear idea of what had happened. "If you didn't order the mercenaries to leave the camp, this wouldn't have happened. Your thirst for glory left us open to an attack!"

Phloria's right hook put an end to the argument, breaking Kortus's jaw, cheekbone, and sending him tumbling on the ground until a carriage stopped him.

"In case you've already forgotten, there's still people in the caves who need our help. All those who are combat-ready follow me. We need to open that door!" She looked at the sky, hoping to see the Friya's guildmates back.

They were all mages and Phlroia could use some backup. Yet she couldn't afford to wait and charged at the entrance now sealed by stone. A tier three earth magic spell, Implosion, made the wall collapse safely, only for it to reform a second later.

It would have been long enough for Phloria to Blink inside, but doing it would also mean to leave the soldiers without a leader nor orders to follow.

'Gods, I wish Lith was here. He would find the Ghouls in the walls in no time with Life Vision, whereas I have to waste time casting an array.' She thought, hoping that Friya could buy her enough time.

Meanwhile, inside the caves, Quylla was fighting for her life. Mage Slayers were true to their name and required a talented fighter to beat them. Until that moment, the elite soldiers had managed to prevent casualties by teaming up and drinking potions.

The former allowed them to overpower the undead with numbers and the latter to bridge most of the gap in their physical prowess. Yet the situation was slowly getting worse.

Mage Slayers wouldn't get tired and while they couldn't be hurt unless their heart was hit, every small cut the mage soldiers suffered would drain their energies faster. The Prospectors were Wardens, and arrays not only required a long cast time, but would also affect their allies as well.

A melee fight was too chaotic to throw a random spell and hope it would hit the right target. Even the soldiers that used rings or wands to instantly conjure darkness bullets ended up hitting only the orange mist that comprised the Slayer's bodies.

To make matters worse, the undead were capable of conjuring spells with no notice, simply by swinging their weapons.

'Think, Quylla, think. It's an easy problem. All I have to do is to reveal their hearts without using magic since it would strengthen them nor swordplay because I suck at it.' Her thoughts oozed sarcasm.

'Messing with the ground is not an option because they are frigging gas. Air magic would blow the mist away if it didn't feed on mana. What the heck can I do? The only physical parts a Mage Slayer has are the heart and the weapon…'

A crazy idea formed in her head as she dodged a stray lightning bolt and took her Royal Forgemaster wand out of her pocket.

"Keep him still for a second!" Quylla yelled at the three soldiers surrounding the undead who was actually female.

They already had a hard time dodging the blade of the Mage Slayer and the spells it conjured, but the mage soldiers obeyed nonetheless. Quylla wore the uniform of the Assistant Professors of the White Griffon academy, so they assumed that she had to be competent.

Moreover, all their attacks until that moment had failed, leaving the mage soldiers open to suggestions. Noor emitted a sound that sounded like a sneer and resumed her assault.

Even though a Mage Slayer's body was made of mist, the strength behind each of their strikes was greater than that of any mortal and each one of them in life had been a blade master.

If not for the body enhancing potions the soldiers had drunk, they wouldn't even be able to follow Noor's movements. The mage soldiers could only dodge or deflect, because the last person to attempt a block had their wrist broken on impact.

One of them moved behind the undead, unleashing a tier two darkness spell aimed to her head that dispersed the mist. It dealt no damage but disrupted the Mage Slayer's perceptions enough for the other two to block her floating blade with a scissor maneuver.

Quylla knew that even by joining their efforts they couldn't hold for long against an unrelenting enemy. Yet a second was all she needed. A silvery strand that resembled a thin whip came out of her wand and wrapped the blade.

When Quylla activated her Forgemaster spell, Clean Slate, which traveled through the wand and its strand, affecting the magical blade as if Quylla was touching it.

Clean Slate generated a combined pulse of light and darkness magic that would temporarily short circuit the imprint on a magical item. In the case of the Mage Slayer, her blade was her own life.

Contrary to what many believed, the weapon of a Mage Slayer would become part of their bodies after they were turned into undead. The blood core and the pseudo core were linked, allowing the enchanted blade to grow in strength over time along with its master.

The magical short circuit caused the life force of the Mage Slayer to flood the blade in the attempt to jump-start its pseudo core. Yet until the effects of Clean Slate faded, their bond would remain broken.

The orange mist suddenly disappeared and without its cover, it took Quylla but a tier one spell to destroy Noor's heart.

"Forget the hearts and destroy their weapons. That's their real weak point!"

The mage soldier switched their blades with maces, so that each hit delivered or taken would weaken the thin weapons the undead used.

"Good to know, sis." Friya appeared right beside Quylla, enveloped by the blue aura of Full Guard and the golden sparkles of light from her personal tier five spell, Dimensional Ruler.

The former was a common Mage Knight spell, that created a spherical blue aura with a radius of 1.65 meters (5.41 feet) around its caster.

Thanks to Full Guard, a Mage Knight had no blind spots. Whatever entered the sphere would be detected, allowing Friya to counter-attack and dodge with surgical precision without even looking.

The latter, instead, did exactly what its name implied, bending the rules of the battlefield to her whims. Used in combination, they granted Friya a full dimensional awareness and a mastery over space limited solely by her imagination.

The Mage Slayers didn't like Quylla disclosing a secret that had gone unnoticed for millennia and were determined to not leaving any witness of the revelation alive. Even beasts and Awakened were unaware of how deep the bond between the undead and their weapons were.

In front of a beating heart of flesh and a piece of metal that could be as durable as Orichalcum, no one ever bothered attacking the weapon. Those strong or skilled enough to find the heart would triumph, while everyone else would die.

That was what the Mage Slayers considered the natural order of things and they would do anything to keep it that way.