The surrounding rock shifted and cracked under the force of Vance's will as the tunnel between him and his pursuer collapsed in on itself. Vance found himself scrambling back towards the end of the tunnel, pulling his legs close to himself to avoid the falling dirt and stone.

For the next few seconds, Vance was assaulted by tiny pebbles flung free from the resulting rubble. His ears were ringing from the sudden onslaught of loud noises, and fear made his legs weak.

On repeat, he pictured the moment that the collapse stopped and the demon crawled its way through the debris, ready to tear out his throat. When the chaos stopped, he could still hear the crackling and popping of its strange, oily form from the other side of the new rock 'wall' he'd created.

Vance paid close attention as the seconds turned to minutes. He could hear his enemy clawing at the stone, trying to get through. With each impact of claw against stone, Vance could sense more and more loose material falling between him and his foe.

Vance moved his attention to his waning willpower. He'd used nearly every drop to buy time. Now, he had to find out if it was worth it. With each passing moment, the demon was becoming more aggravated. Vance wasn't sure whether to laugh or cry when the creature stopped its assault after a particularly large boulder tumbled down from above.

"Waiting fine is. Simple spell find will our wrong target once more, bring our me back to it. Special pleasures have we for you, one who is...annoying."

The demon's voice came to Vance as a stench on the wind, foul and all-encompassing. Vance sensed the demon and its weakened dark mana reserve make its way back through the tunnels. Vance knew it was only a matter of time before it retried its ritual and once more, Vance would find himself in its lair. Next time, it wouldn't let him run.

Vance took stock of his exhausted self. He was out of fire mana, his fire core sputtering weakly as it tried to reignite itself. He'd barely slept, and he wasn't precisely in shape. This little sprint had sent his heart into overdrive, though, perhaps that was just the fear.

Vance breathed heavily, sat on the ground, covered in tiny stones. Every other lungful of air brought a few coughs owing to the still settling dust cloud. Shortly thereafter, his adrenaline finally wore off and the rush of pain that came from his myriad tiny wounds brought Vance to a new level of awareness.

He sucked in a cold breath through clenched teeth and held in a shout. Instinctively, Vance began using transference to capture the tiny pieces of dark mana that assaulted him. He pulled it inside himself and surrounded it with ambient mana. For a moment, he considered studying it. He mused that if he could learn to shift dark mana into ambient mana. Doing so would be an invaluable weapon against demons, but he lacked the time for that particular branch of fanciful experimentation.

With each portion he removed, the pain lessened. After a few minutes, he'd cleared up enough of the dark mana that the wounds hurt, as he estimated, a normal amount. Vance took the dark mana and expelled it, pushing it out far away from his body, where it seemed to lose its purpose.

Vance purposely didn't reignite his fire core. For now, it was better it was weak. He stood and reached up to the ceiling, where he placed a hand gently on the large roots that he'd grown over his portion of the tunnel.

"I could really, really use your help." He muttered to nobody in particular, as he used the tiny scraps of his remaining will to reach out to the wood mana therein. He tugged on it gently and slowly willed it towards himself as he lowered himself back down into a seated position. From an outsiders perspective, it would look like he was pulling a root out of the ceiling.

"If a demon is going to kill me anyway, might as well risk this."

Vance sat, holding the end of the root that snaked down from the ceiling in his hands. He held it like it was precious to him, and it was. This root represented hope for Vance.

As gently as he could, Vance began to tug on the mana inside the root. He pulled it into himself slowly, methodically. Vance created a transference shell of ambient mana and guided the wood mana inside. He slowly moved the shell to his stomach. As he did, the stream of wooden mana began to follow the shell as if a moth to a flame.

This was Vance's first time doing this on purpose, but he knew the theory well. As soon as he pushed his will to cement the transference shell in place, the integration would start in earnest. Vance allowed a few minutes to pass to let even a tiny extra portion of his willpower recover, then he, split his attention.

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One part went to his fire core, where he clamped down on the sputtering feather inside. For this to work, he would have to allow it no room to gain momentum. As soon as integration started, it would fight back.

Then, he took a deep breath and cemented the shell in place. It was now, or never.

Vance felt a sudden rush as, with much more ease, wood mana flowed out of the root in his hands and, under Vance's direction, made its way into his forming core.

With the sudden influx of wood mana, so too came nausea. Vance's head was spinning and he was grateful that the room was largely silent. He felt his stomach tighten and contract as if he would vomit, but he fought back the urge.

In that brief instant, he discovered why advanced cores were reputed as much harder to integrate. He'd had to focus on holding his instincts back for just a second and, in that instant, his fire core had pushed against his control, hard.

Vance found himself sweating, and either it was his imagination or the room was getting very warm, very fast. Inwardly, Vance could sense that his fire core was using a portion of his willpower to perform tiny, natural shifts of fire mana. Ordinarily, this wouldn't be a problem, but the construct inside was stirred into life.

Vance didn't have the willpower to properly contend with the construct if it gathered any momentum, so once again, he clamped down hard.

"Shit..." he whispered to himself, having realised that if he'd let his concentration lapse any further, he'd have had no chance. The nausea was getting worse, but his stomach seemed to get the message after a few more difficult reminders that throwing up was not an option.

Vance spent the next hour in this horrible limbo, dancing on the edge of a knife. He didn't have enough willpower to actively, fully suppress his fire core, he had to settle for simply managing it. More than once, tiny flares of fire mana escaped his control and made their way out of the core, burning up some of the trespassing wood mana. Usually, this would occur when Vance would be hit with a particularly tough bout of nausea and would have to catch himself from falling backwards in his disorientation.

As far as he was currently concerned, the outside world was a thing of the past. He didn't have the spare attention for it, and so wasn't aware that the roots on the ceiling had begun curling their tips down towards him.

After the second hour, Vance felt his nausea begin to fade, instead replaced by a different sensation. He felt a sensation like aching in his arms and legs. Absentmindedly, he tried to stretch them out, but they refused to move. Ordinarily, the sudden paralysis of body parts would be cause for panic. Under these circumstances, he still had no attention to spare.

Vance felt the mana in the tree's root dry up after the end of the third hour. His newly forming core was nearly filled to the brim, and he was satisfied. Now, he just had to fend off his fire core for a little longer, the core was nearly fully formed.

Naturally, that's precisely when his will gave out. Abject panic took over and Vance felt his fire core stir. Dense fire mana began to perpetuate itself deep within, surrounding the feather construct. To Vance, the flames seemed as if they coiled up, like a snake preparing to strike.

As it built momentum, Vance could only think of one thing to do, so he leapt across the room, putting himself closer to the dark mana that was still present in the area. Vance knew his fire core was special, and he'd learned something new about it today, something he would try to exploit.

It hated demons, and hopefully by extension, dark mana. Vance ran into the remaining particulates of dark mana, which quickly resumed their original purpose of assaulting Vance's open wounds. Vance held his breath in anticipation and prepared to reach for his already exhausted will, hoping beyond hope that he had enough to protect his new core.

Then, the flames rushed out of his fire core and instead of attacking the wood mana, they prioritised. Vance found himself covered in dozens of tiny flicks of fire that fought off the dark mana. It was so tiny and hard to pin down that the flames had to take the scorched earth approach, and spent far more mana than they destroyed.

Vance reluctantly celebrated inwardly and paid close attention, waiting for his core to change its mind. He didn't want to think about what would happen if he lost control of all of that wood mana with his will in its current shape. As the dark mana dwindled, Vance felt fear beginning to take hold once again. At that moment, by some divine grace, Vance felt his new core suddenly solidify, and the integration was finally complete.

It started like a rush going to his head as if he'd stood up too quickly. At some point, control of his arms and legs had come back to him. His will was still entirely drained, but he could feel the mana stirring in his newly formed wood core, begging to be used. He wasn't sure if that was just a trick of his senses, maybe a form of excitement. Either way, he felt euphoric.

Then, as quickly as it came, the headrush faded and he fell backwards, exhausted, flat onto his ass. He'd succeeded in forming his second core, an advanced core, no less. His friends and teachers would be so very proud of him.

If he survived.

No matter what, he would need to rest. With his willpower how it was, there was almost no chance of him controlling the mana in either of his cores. Acting now would only make things worse, so he had to risk waiting. He pulled in his mana sense, shutting himself off from the outside world. He let his fire mana come to rest in his core, where it began to perpetuate. Luckily, he had time before the amount was truly threatening once again.

Like this, Vance sat in total, unbroken silence, locked in a tiny room, and prepared himself.