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A dark cloud hovered over the heads of the monster kingdom. Every member of their society was under an unspeakable amount of grief but no one suffered more than the king and queen.
The prince and their adopted child were dead.
Asgore's thunderous roars of anguish could be heard as far as the ruins. Toriel was overcome with sorrow. The kingdom was all but shut down for days. No voice complained and everyone mourned the death of their rulers' beloved children. A parade and funeral were held in their honor to spread the ashes and celebrate the short lives of the children. Gaster stood beside the king, offering all he could. Asgore came to him both in tear and in rage. He asked Gaster frequently for two things, to reverse time or for revenge. As much as Gaster would love to bring the dead children back, revenge was all he could offer. Fortunately, it's all Asgore seemed to desire once his sorrow left him.
At the end of the funeral, Asgore made an announcement to the entire underground. The humans would pay for what they have done. The secret to destroying the barrier was not hidden, however when the first human fell Toriel and Asgore lacked the strength to do what they needed. To be fair, Gaster didn't find out about the true detailed power of human souls until that human fell. When he informed Asgore, the king gave him the coldest look Gaster had ever felt. It chilled him down to his marrow as the king's deep voice ordered him to find another way. Now, that very king told him to do it the only way they knew how.
Asgore told the land that every human that fell was to be taken to him. That with seven human souls, the barrier would be lifted and they would be free. Free from the mountain they were imprisoned in. Free to expand and grow. Free to seek out the revenge they deserved against the human that not only trapped them but murder their kingdom's prince. The monsters were riled up by their speech but Toriel was horrified. She demanded answers and why Asgore had never discussed these ideas with her. The two fought, more than they ever had.
Gaster watched as their once perfect and happy family turned to dust. He thought about children once more. Their importance. Their impact. Was it because of their death that this happened? Was Asriel keeping them together? Gaster couldn't know, though it seemed like it. He wondered how his own children would affect him. With no spouse, what would they bring to him? Joy? Pain? Would he be rewarded with love? What if something were to happen to them? Would he grieve like Toriel or seek revenge like Asgore?
Gaster had very little time to think it over, for soon after Asgore's announcement, a human fell. Two days after it was known, Asgore came to Gaster with a cyan soul. Asgore spoke no words but his appears told Gaster everything he needed. One fist was clenched, the smell of fire magic coming off. On the feet of his armor was blood and Gaster swallowed. His eyes were cold, filled with sorrow and hate. For what it was directed at the doctor did not know. The doctor didn't wish to find out either. He locked the soul away in a protective case and held it for Asgore.
Toriel was once again furious. Asgore murdered a child and she was disgusted. She cried, hit, even slept in a different room unable to even look at her husband. Gaster avoided their toxic home, instead, studying the one soul he had. It offered new information and without fear or hurting the child it came with, Gaster was free to do more than he was able to with the king's child.
It took a year before the next fall. Then twenty years. Then five years. Then thirty-seven. Then, the last took one hundred and eighty-five.
Each one was different. Some killed, some didn't. Some were kind and pleaded for mercy while others were filled with hate. No matter what they were like, they all fell at the hand of Asgore. No matter how hard Toriel tried to save them, no matter how hard the human fought or begged, Gaster always got their soul at the end of the day. After the final human, Toriel left taking the grave of her child with her to be properly buried and loved. Away from the monster, Asgore had become and the home that no longer held love.
Gaster remained loyal to Asgore and watched him become hollow and empty. Each death took a toll on him. One so grave Gaster offer to handle the humans himself but Asgore forbade him. When Toriel left Asgore had no other path and could no longer go back. He told his people they needed only one more soul but the length of that last one had the kingdom finding little solace in the king's word. Many feared humans and feared to leave. They didn't believe escape was possible or it would be too far away for them to see.
Their doubt is what fueled Gaster.
One more soul. One. They were so close to freedom yet so very few believe in it still. Who knows when the next human would fall. If Gaster was honest, he didn't think it possible, at least not in his lifetime. Which is why he studied and spent all possible time on the souls. There had to be a secret to them, a way to explain them. With one soul, Gaster even debated making one.
Would it even be possible? Create a soul? A human one at that? No one even knew what a soul was made of. Gaster figured determination is what kept human souls so eternal and everlasting. Monster lacked that and could not handle it. Gaster also hypothesis monster had more of an intuition for their souls. Their trust, love, and 'feelings' are what made their soul the way it is. Hence why so many were weak and why once the monster was dead the soul was too.
Gaster couldn't bottle up feeling, though. He couldn't mix up emotions to create something, they needed to be solid. He could extract things from the souls, but the raw power was not the same as the refined one the soul itself was. Gaster didn't know how to make it that way either.
A soul. That required more than science. It needed magic, genetics, some say love and a family. What if in creating a soul he created actual life instead?
Gaster stared down at his work desk. Creating life. Was that was he was doing? A soul was life to a monster. What if he made a monster?
A faded memory struck Gaster's mind. One of the small prince waving at him. Innocent. Sweet. A child. Could Gaster create that?
His soul started to beat in his ribs. No. That was madness. He couldn't. But could he? No! He had a job to do. He needed a soul, not a child. But what if? By accident? Were human souls easier to make? What type of soul was he to make? What if it did turn into a monster? What kind? Did he need to prepare for that?
Without realizing it Gaster found himself writing, hypothesizing, experimenting. There were so many possibilities. So many outcomes. No matter what he did one of them had to be true. So he'd create a soul, was that so bad? With no real intentions of a child was he doing any harm? Of course not! He was doing this for the kingdom. A final soul for the kingdom. He was just, also preparing. Being sensible. He had to prepare for all outcomes. A soul, a monster soul-NO! A prototype. No monster. No human. A basic soul, stronger than a monster but weaker than a human. A balance Gaster could test and fiddle with. That would do! That would be perfect!
Gaster now tried to convince himself it wasn't for his personal gain. No, this was for science. Science made him think of these outcomes. Logically, if the soul did turn into a monster he needed it to live and reflect something he wanted, right? Using Gaster's magic and properties seemed only natural. It was secret after all. No one would be working on this but him, it had to be him. So the soul had to turn into a skeleton monster. If the soul was to become anything of course. That was only fair. Gaster was a skeleton, after all, he was a bit biased of his race so if this soul became alive a skeleton would be perfect! Plus if it did turn human to some degree it would also work! Humans had a skeleton in them. It all worked out! A skeleton monster it would become.
If it did transform that is. Gaster couldn't try to make it. This wasn't about him. It was about the soul. All he could do was prepare it.
“For science,” Gaster muttered, watching the vial fill up with his magic. The needle pierced his soul getting the energy it needed. The doctor needed a lot of samples, magic, marrow, even bone. If he were to be the example for this soul he needed to know about himself more than he thought possible. Test after test, sample after sample.
“One sample,” Gaster muttered, body trembling as he outlined a circle in his non-dominate hand. He placed it under the machine with the same circle and strapped his arm down. With a deep breath, the doctor pressed the button and the machine came down and Gaster screamed.
“Gaster!” Asgore gasped and the doctor jumped. “What on earth happened to your hand?!”
“Burned it, that's all. Someone forgot to turn off the burner. Rested my hand right on it,” Gaster lied, holding his bandaged hand. He needed more samples and instead of chipping away bone after bone, Gaster decided one large one would be enough.
“Are you alright? Did you see a doctor?”
“Yes, do not worry I'll be fine Asgore.” Gaster smiled.
“At least take a day off. You can't possible work one handed.” Gaster opened his mouth to protest but then thought about the soul.
“...Alright.” More time to work on his soul? Gaster would humbly accept. In just four months he had gathered enough data and samples to begin construction. Unable to find a womb or something to properly nurture the soul with, Gaster created his own artificial, fleshy sac and began one step at a time, injecting it with the samples. He started with his own, a needle feeding the sack the magic Gaster collected as he took a syringe and began feeding it his altered marrow and other samples to hopefully create the monster form. Once all of his samples were in he began working on the overall monster soul mixture. Although feeling were hard to turn into a liquid, soul energy wasn't. Multiple samples, dissected, picked, and scanned had been looked over and examined to get what Gaster assumed to be the closest he could to the details of a monster's soul. One drop at a time, they entered the sac mixing with Gaster's samples. With no reaction yet, the doctor sighed shakily and check to ensure his magic supply was still dripping into the soul. With the magic IV intact still, Gaster then stuck in another IV of deluded human magic. He added just a single drop to a large portion of his own solution and nutrients that would hopefully both give the soul the extra power it needed while also keeping the soul healthy. Human magic was dangerous and too much would or could damage the soul. For now, Gaster decided he'd take it a drop at a time. With a deep breath, Gaster set the creation in a medium sized tube of warm, plain magic similar to that a monster baby would be in.
He stepped back and watched, waiting for something but nothing happened. The soul floated but did not beat or come alive in any extravagant manner. Both disappointed and expected, Gaster cleaned up and took some notes. He shouldn't expect much from this. It was a prototype after all. As if Gaster's first attempt would turn into anything worthwhile. If he was lucky it would do anything at all.
This was merely a test. Step one of many. Now all he needed to do was wait. If the soul came to life, Gaster succeeded. If it didn't, he'd try again until it did.
Of course, the Gaster doubted his skill. Gaster doubted himself often. He believed everyone should. No one is perfect and if one truly believed they were, chances are they really aren't nearly as great as they thought. Gaster was aware he was wiser than most, his degrees and test scored proved so. However, he never figured he'd be capable of doing things with just one try. He couldn't master a language in a day. He couldn't read a book and know the every word after one go. He couldn't even assume his first calculations were correct.
Yet, two days later, floating there in that tube rested a monster's soul. Alive. Beating. Feeling.
Gaster was over the moon. His experiment worked. He created a soul! This changed so many things! So many more possibilities. Strong ones, weaker ones, human ones! Was there a limit to these souls? Could he replicate the human souls he had? Could he create a human? A monster? Would the soul he had become one?
Gaster jumped when an alarm sounded. He looked around for the cause before his eyes landed the soul's stats. Low magic? How was that possible? Gaster fed it twice the amount needed for a regular child!
Another alarm. The cyan magic was failing.
Another alarm. The soul was dying.
Gaster felt a numbing chill shoot down his spine. Glancing at the soul for just a moment he tore off the lid to the machine and grabbed the main feeding IV. It was too early for the next dose but the soul needed to remain stable while the doctor worked. Gaster stuck the IV into the soul one alarm silenced. Stable for now but the magic was still low. Why? Did Gaster need more monster magic? That wouldn't help the cyan, though. Adding more cyan was a risk as well. So why was that failing? Human magic and monsters were similar only minus the determination.
Gaster held his breath and looked at the soul. Determination? Was that it? But the soul was a monster's now. Determination would kill it. The determination wouldn't help the monster magic levels. Gaster made it partially a human's as well. Humans needed determination. But the risk. How much? Injecting it could kill the soul even with stabilizing the cyan. The cyan and determination still wouldn't stabilize the monster magic! Would it overpower it? Take over? Make it human? Gaster wanted a monster, not a human!
But what other choice was there? Monster magic wouldn't do. Gaster didn't create a monster, he created some monster hybrid. No, he didn't create a monster at all. This was about the soul. And if the soul needed determination he'd give it determination.
“Hold on,” Gaster told the soul before he fled the room. He ran to his samples and data area and scanned it for the items he needed. The determination was easy to spot. He snatched the bright red vial up along with three more bags for the IV and the cyan for good measure. Gaster scanned shelf after shelf of his magic and cursed when he came up empty. He had no time to drain the needed amount. Stuffing the items into his pocket Gaster grabbed several needles of different sizes unsure which would be needed for a transfusion. Grabbed more thing than needed, Gaster darted back over to the soul and dumped everything onto the desk. He got to work on the determination, his trembling hands removing a few drops from the syrupy magic. Setting the vial down he hung up the new IV bag and injected a single drop into the bag. Gaster cringed at the faded pink color the bag turned. Only a drop and it seemed like so much. He then filled another syringe up with the cyan and injected only a drop into the soul.
Setting down the shot Gaster summoned his soul. The shuffled around the needles gaging the size before he fiddles with the numerous components until he got the transfusion tube. He stuck in the tiny needle on the other end before he grabbed his own side. With a deep breath, Gaster pierced his soul and he bit down to suppress his shout. Trembling still, Gaster wasted no time in removing the stabilizing IV and replacing it with the determination and his own magic injection. The alarms beeped and blared around him, the soul itself pulsating.
The soul radiated a jolt of magic that startled Gaster but the cyan alarm stopped. It pulsated, flashes of cyan appearing in the gray monster soul. He looked at the chart and sighed relieved it worked. The relief was short lived. The cyan levels rose and the monster magic level plummeted. The soul was now vibrating, flashes dull hues of cyan and red. Had the determination been too much? One drop diluted that much still caused the soul to melt down?
Gaster suddenly felt his soul constrict. He let out a yelp, grabbing the from of his chest as his soul ached and throbbed. The soul in the tank pulsated madly, flickering between pink, cyan, and purple. The doctor groaned, a fiery pain spreading through his chest, numbing his legs. He struggled to breathe, vision whiting out during a wave of the agony. Gaster felt weak as the soul drained his magic. It was trying to balance out. Taking Gaster's magic to fight off the determination. But Gaster didn't have nearly enough to fight it.
Gaster fell to his knees, entire body burning but he had no energy. He could barely focus on the screens. The alarms blurred together sounding so far away and his vision began to blacken around the edges. The cyan continued to rise, almost a straight line as it shot up. The monster magic was failing, the soul dying and Gaster cursed. The alarms rang, shrieking yet whispering at Gaster and the doctor struggled to even remain upright. He reached out, needing to remove the needle from his soul. The experiment was draining him. He had to stop. The soul would die but Gaster had to.
Right as Gaster grabbed his soul the experiment flashed a brilliant purple and Gaster released his soul in favor of cradling his face. His socket felt as if it was splitting. Gaster released a loud scream challenging the blaring alarms. Neither could be heard to Gaster, his hearing all but muted minus an audible crack. He could feel his throat become shredded by his screaming. He could feel the crack form under his hands. He could hear it echoing in his mind. Even still the world was slowed and blurred. The reality of it all was there, yet Gaster lacked the ability to act upon it. The doctor pulled one hand away and stared down at it. Marrow and dust covered it but the doctor had very little time to fear before his socket erupted a charge of magic and a crack split from the tip of his right eye to halfway down his skull. Gaster's didn't even scream. His pupils just vanished as he fell to the ground his soul faded back into him.