God Ash: Remnants of the fallen.

Zombies...

Humanoid creatures created by the Devilish corruption of a man's body and soul. They sought human flesh and could smell human blood from a mile away.

'Can {Zombie} blood be a good mana catalyst?'

While Devil Essence was the main determinant of Devilish corruption, the different strains of mana also played a heavy part in the mutation.

Not only that, but different {Zombies} possessed different abilities. Some were fast, some possessed brute strength, and others could even use magic.

Right now, Cain stood inside the upper floor of one of the only taller buildings still standing. In there, he was able to see the overwhelming sea of zombies treading down below.

As long as they couldn't see, hear, or smell humans, the Zombies were pretty docile abominations. Peaceful, but abominations nonetheless...

They shuffled around the desiccated streets, their eyes hollow and blank, yet containing infinite pain and suffering. It was as though their souls were locked in eternal torment.

And then, there were the horde masters;

The {Miasma Devils}...

Just like how every human was different, every Devil also had differences. The {Miasma Devils} were beings in charge of controlling the hordes of {Zombies}.

The zombie hordes were used by the Devils for many things, not limited to, but including building several outposts scattered around the City, just like the one Cain and the others had encountered.

Within the City, they were used to harass the humans, occasionally attacking the domes. They were also used to spread the harrowing rot of Devil Essence through the entire City.

Their final and most important use, was sustenance. Devils, like other living beings, needed food. Creating zombies was like tending to a field. Once the crops were ripe, they would be picked and devoured whole.

It was terrifying and despicable, at least from a humans standpoint. In reality, it was just the nature of things.

One ate and the other would get eaten...

Although the Devils were an anomaly to normal life, they couldn't go against this reality.

"So how are we going to get past this?" Cain asked Boulder.

Currently, all twenty of them were scattered within this building. They had met up with Lucia and Khan at some point as well.

As long as they got past this point without alerting the Zombies, or their masters, they would get to their location without any casualties.

Boulder was silent for a moment before speaking,

"Well, we don't. We wait for them to get past us."

Cain sighed, "Well, the horde moves, that's true. But it's so slow."

Khan nodded, "They can only stay in one place for so long. They can move faster, but they do this to preserve energy. The Devils feed them mana and Devils Essence, but it takes some time for the non-elemental strain of mana to be converted into blood elemental mana, which can be converted into biological matter, and so on..."

Cain raised a brow, 'He seems quite knowledgeable about these things...'

Lucia leaned in and explained, "He has a frightening obsession with all things magic that affect living beings."

Khan chuckled, "I wouldn't call it an obsession, but I do admit it does fascinate me."

The smile on his face became wider,

"Isn't it exciting? What was once a thriving civilization of humans, reduced to a rotting mess. How did it happen? Is Devilish Essence the only culprit for this, or is our very human nature a contributing factor. After all, Mutant Creatures exposed to Devil Essence aren't corrupted in this manner. So many things to consider."

Cain's eyes were wide open, "I see..."

Lucia snorted, "See? He's completely obsessed."

Boulder clapped lightly, "Alright, that's enough fooling around. All we can do now is wait for the horde to pass over. Khan, you and I will be on the lookout."

Khan nodded, "I heard there's been several new breeds of zombies appearing in the hordes these days. I hope nothing too crazy is going to happen."

Boulder shrugged as he got up, "If you ask me, I think it's a sign..."

Cain narrowed his eyes,

"A sign?"

Boulder nodded. As he casually walked towards the door, a mysterious air enveloped him,

"A sign that things are about to change."

And with that, he left the room, leaving Cain to his thoughts.

'A change... What could he mean by that?'

If he didn't think about it deeply, then what Boulder said didn't sound all too bad. However, if there was a hidden meaning behind it, then things were far more ominous that they seemed.

Considering they were currently surrounded by a bumbling sea of semi-rotten corpses, if things got even more ominous than this, then it was trouble. Big trouble...

They scattered around the building because it was possible for the zombies to pick up the concentrated body heat signals released by humans.

Right now he was alone in this room together with Lucia.

He stared at the beautiful yet ferocious woman from the corner of his vision, afraid she would make a fuss if she caught his staring.

Her eyes were shut, probably to avoid interacting with him. He had no way of knowing what was going on in her mind, but from what he had seen so far, he could tell she didn't like him very much.

However he wasn't very bothered...

'She's cute and all, but I think girls like Susan and Jenny are far better. Like a breath of fresh, salty sea air after being locked indoors all day, or the first rays of golden morning sun. Yeah, that's it...'

Lucia suddenly snapped her eyes open. Cain hurriedly diverted his gaze.

"You don't have to be sneaky. Stare if you want."

Cain cleared his throat, "What do you mean? I wasn't staring."

Lucia rolled her eyes,

"Sure, sure."

Silence descended once again...

Cain decided not to hide it anymore. One shouldn't be ashamed of appreciating beauty...

After some time, he closed his eyes...

His consciousness traveled into his mind. That place where his skills were created.

A mental whiteboard, was what he liked to call it.

In here, he was able to not only create skills and spells quickly, here, he was also able to analyze, deconstruct, and modify skills, spells, and abilities.

Right now, he planned on doing something that had been on his mind for some time now.

Although he had thought about it, so far, he hadn't been very successful.

'How do I improve {Mana Heart}...'

As he was, Cain realized he didn't need any more skills, spells, or abilities. It was the quality of his repertoire that was suffering.

His abilities were created by a Tierless being, so obviously, he had those proportions in mind when the magic circles the skills and spells wer centered around.

They had undergone some changes when he had transcended tiers, but the changes, now that he had become truly Tier 1, felt insignificant.

The thought had entered his mind first when he had battled against the {Herald of Darkness}, and now, as he observed the roaming zombies.

So to further improve himself, he had to improve his fundamentals. And so, he had decided to begin with {Mana Heart}.

The problem here, was the way the skill, {Mana Heart} had been created.

Generally, there were two types of skills, spells, and abilities. Those created by the individual, and this granted by the system.

The skills granted by the system were also separated into two classes; those granted to him when he had killed a Mutant Creature or Devil, and those granted when he had performed an act, or accomplished an achievement.

{Mana Heart} was created when he had created the [Body and Soul] contract with Ruby.

It was created to a human equivalent to a mana shard or core. A mana shard acted usually as a mana storage organ. It also doubled as a mana refinery and output controller.

To put it simply, it allowed a Mutant Creature extra mana retention and usage, compared to humans who had to earn and create such abilities by themselves.

The skill, {Mana Heart} had served him well. But there was no way it would still be as useful as it had been back then.

It needed a fundamental change.

And there was only one way to do it.

But the problem arose here; he needed to change a skill he hadn't created by himself.

In fact, calling {Mana Heart} a skill wasn't entirely accurate. It has transcended being just a skill. Instead, it had become a part of him. It was practically an entire organ.

And as an organ, messing with the skill itself meant he was messing with a part of his body.

He had no idea what other changes the {Mana Heart} had brought to his body. Messing with it recklessly could have adverse effects.

The {Mana Heart} skill's main magic circle had several parts, but its main part functioned as a mana shard. He could improve on this, or he could add other parts to it.

It was difficult to make a decision, especially one that could negatively affect him. Right now, he had to make sure he stayed in top shape before the battle.

But then, a thought entered his head.

A thought, that stuck to him like glue, almost impossible to get rid of...

'What if a second heart is created?'