Years passed by. Gaster built The Core as fast as he could and the Underground began to think of him as a hero who had given them not only power but hope of the future as Gaster announced that he was beginning to research the barrier. His employees seemed to worship him, soon becoming known as his Followers instead.
Gaster was happy with his work if not a bit stressed. He was rarely at his house he had bought in Snowdin, even when he was in Snowdin he spent most of his time in Grillby's bar. Spending time with his old friend.
He also spent a lot of time with the King and Queen. He'd go over to give them reports and end up staying for tea or lunch or dinner and then he'd spend time with the Royal family. He always really liked kids but it was harder to be around them since his nieces and nephews were killed, it brought back painful memories. Prince Asriel seemed to take a liking to him, however. He didn't know why and he tried to keep away from the Young Prince as much as he could...
Then one day when Gaster came in to give a report and Asriel came running over to him and hugged his leg. "Yay! Uncle Gaster's here!" He had called out to his parents.
Being called "Uncle" again had triggered memories he'd rather forget. Memories of his family he had lost. Like the first time his eldest sister, Ariel, told him, his brothers and other sisters that they were going to be aunties and uncles to memories of all the little babybones, first words, all the time he spent teaching them and playing with them...
He managed not to show his distress over something so small only because the Prince had called him "Uncle Gaster" not "Uncle Wingdings."
He still asked the King and Queen about it. They laughed and told him that Asriel really liked him and thought he was cool. As much as Gaster acted like he disapproved of it and as much as it brought back horrid memories he felt happy, it was like he really was gaining a new family in the Royal Family as well as in Grillby's.
Without really noticing it, Gaster grew closer to Prince Asriel. He would sit with the young prince and help him with his homework and he'd sometimes get dragged out to the Ruins with the Royal Family and end up joining the Prince and King in their games. It was fun but Gaster tried to keep it to a minimum, he had work to do.
He disapproved of Chara. Humans were nothing but bad news and even though Asgore and Toriel had hopes that adopting a human child would help negotiations when Gaster inevitably opened the barrier (even though he was far from it.) Gaster couldn't help but fear that Chara would be the end of them. He distrusted humans and he could see that Chara wasn't exactly a good person.
He kept a close eye on them. He wanted very much to experiment on them, there was so much he could learn by dissecting them or ripping out their soul and doing tests on that... But he couldn't do that, even if they weren't the King and Queen's child that would still be very much illegal. They were a living thing and therefore had rights. Besides they were a child, Gaster didn't know if he'd really be able to bring himself to harm a child. So Gaster kept those thoughts to himself and watched Chara carefully trying to learn everything he could from simply observing them.
He also tried to keep a close eye on Asriel. He didn't trust Chara, humans were evil and he didn't want the Prince to get hurt...
Then Chara became sick. They died.
Gaster had been in his lab, working on improving The Core when one of his Followers came running in.
"Dr Gaster!" He called running over in a panic, "Chara has died!"
Gaster nodded, Chara had been sick for a long time so news that they'd died didn't really shock him all that much, it was only a matter of time. He had tried to save them, really he did, but in the end they couldn't be saved.
"I'LL VISIT ASGORE AND TORIEL LATER TO OVER MY CONDOLENCES," He told his Follower, not even looking up for his computer screen that displaced a long page of code written in wingdings.
"Doctor, they require your presence now..."
"WHY? I'M VERY BUSY."
"Prince Asriel took Chara's soul."
This caught Gaster's attention and he turned fast. "REALLY? WHAT HAPPENED? I MUST STUDY HIM NOW!" Gaster stood up, he had no time to remove his lab coat and put on his hoodie or coat as he walked towards the door.
"Wait! Doctor Gaster!" His Follower stopped him by grabbing his sleeve and then ran round to block his path. "He took the soul and crossed the barrier with Chara... The humans... They... They thought he'd... Killed Chara, they attacked him..."
Gaster felt a cold chill run down his spine... Asriel had been like a nephew to him... He couldn't lose him as well... "HOW IS HE?" Gaster demanded but got no reply. "PLEASE TELL ME THE PRINCE IS ALIVE!"
"Prince Asriel was killed by humans."
Gaster turned and ran out of the door without another word after pushing his Follower out of the way. He ran as fast as he could to the castle. He could believe it, the Prince was dead... He'd cared for the boy but he hadn't shown it enough and he regretted that. He regretted so much. The humans had taken from him again... How much more could they hurt him.
He wanted them dead. Every. Last. One. Dead. Once he got out of the barrier he'd make them all pay, he'd do anything to kill all humans, anything. Even if that meant trading his soul and pushing away his new family...
He was filled with rage and hate.
He burst into the throne room. Asgore and Toriel were sitting on the floor, holding each other tightly as they cried. Gaster ran to them, panting and out of breath he spoke as he fell to his knees in front of his friends, "I AM SO, SO SORRY."
They said nothing but pulled Gaster in for an embrace. The three monsters who had all lost so much sat on the floor and cried on each other's shoulders. Nothing would be the same again. All hope was lost.
"What are we going to do?" Toriel whispered, once the three had calmed down a little.
"WE NEED TO MAKE THE HUMANS PAY," Gaster said not even trying to sound calm. "THEY TOOK EVERYTHING FROM ME AND YET THEY TAKE MORE. I SWEAR I'LL KILL THEM ALL."
"Gaster... That's not the way," Toriel scolded him, "we want peace and humans are stronger than us! Besides more death with just spell the end for everyone." She looked Gaster in the eye and pointed to his empty socket. "An eye for an eye makes the whole world blind."
Gaster sighed at her and looked away. "I DON'T REALLY CARE. I WANT THEM DEAD AND IF THAT MAKES ME A BAD PERSON THEN I GUESS I AM ONE. NOTHING ELSE MATTERS TO ME, MY SPECIES WILL DIE WITH ME AND IT'S THEIR FAULT. I CAN'T FORGIVE THEM."
"You're not thinking straight, Gaster! Asgore, help me talk some sense into him!"
Asgore looked down at the ground, a frown on his face and his hands in fists. "No, he's right Tori, we can't let this go unpunished. We can't just let the humans walk all over us. They wiped out many species of monsters, they killed Gaster's whole family, every skeleton, and now they've taken my son."
Toriel looked at her husband in horror. "You've got to be kidding me! Asgore, you can't!"
He ignored her and turned to Gaster. "You said we'd need human souls or something with the power equal to human souls to open the barrier?"
Gaster nodded, "YES, I HAVE SPEND A GREAT AMOUNT OF TIME STUDYING THE BARRIER. IT'S THE ONLY WAY TO OPEN IT."
"Tell me again, how many souls will we need?" Asgore asked.
Toriel gasped, "Asgore, no you can't! I won't let you take human souls!"
Gaster hesitated, as much as he wanted revenge he couldn't let the King do it, he could do it. He couldn't let the King kill innocent people, he was too kind. It should be Gaster's burden to bear, he was the one who'd lost the most, he had nothing left to lose, Asgore had a lot to lose.
"How many?" Asgore asked again, firmer than before.
Gaster fixed his glasses and looked to the Queen who was giving him a firm look. "SEVEN... WE'LL NEED SEVEN HUMAN SOULS."
Asgore nodded and stood. "Seven..." he repeated as he stood up, "we'll get those souls. Chara fell so there will be more, we'll take the souls of those humans."
"You'll have to kill them..." Toriel said standing up and glaring at Asgore. "I won't let you do that! You will not kill innocent children."
Toriel was preparing a magical attack.
Gaster stood next to Toriel. "I AGREE WITH TORIEL," he said. The King and Queen both looked at him in shock, they both had thought he'd be on Asgore's side. "MY KING, I CANNOT LET YOU KILL CHILDREN, YOU ARE NOT THE KIND OF PERSON TO DO THAT."
"You do not know if the humans who fall will all be children, they could be adults." Asgore turned away and began to walk towards the balcony.
"THEY COULD BE CHILDREN."
"Even if they are adults they are still innocent!" Toriel called as she ran in front of Asgore to block his path.
"You don't know that. They might be bad people. Even if they're not we can't wait for bad people to fall it'll take too long. I'm doing this for the people, they deserve freedom, from the Underground, from humans. I will do what I must."
Tears were running down the Queen's face. "We have to take the moral high ground, be better than the humans! I will not let you stoop to their level!"
"I don't care, I want revenge. Asriel deserves that or he died for nothing... Tori please don't get in my way. I don't want to fight you."
"Don't 'Tori' me! You're angry I understand, I am too but this isn't the answer!" She threw a fireball at him. Asgore threw one back, they were fighting. Fire flying back and forth, either hitting, whether that was because they missed on purpose or if they were dodging Gaster didn't know nor care.
Gaster just stood at the side not knowing what to do. He didn't want his friends to fight... "I THINK WE ALL NEED TO CALM DOWN AND TALK THINGS THROUGH. PERHAPS WE SHOULD CALL THE OTHER COURT MEMBERS HERE?" He said, he had to stop them. The Underground needed them more than ever, they couldn't fight now, as much as Gaster wanted to side with the King, he needed to be the voice of reason. He had to stay neutral. Gaster summoned two magic hands and used them to push Asgore and Toriel back a little, not wanting to risk putting himself in danger.
Asgore turned around to face him. "Don't you dare try to stop me, Gaster! You want revenge as much as I do! You can't let the humans get away with the mass genocide of your people!"
"I WON'T! BUT I WILL NOT LET YOU BEAR THE BURDEN, THERE MUST BE ANOTHER WAY! A WAY THAT LET'S US HAVE REVENGE WITHOUT KILLING CHILDREN!"
"My mind is made. I will do this, it's for the greater good."
"Asgore, I will not fight you but know this, if you do this I'm leaving you." Toriel stood firm. "I'll protect the humans from you if I have to!"
Asgore looked hurt by what the Queen had said but he did not back down. "So be it." He walked forward, pushing past his soon to be ex-wife and stepped out onto the balcony.
Monsters had gathered, having heard the news, they crowded around desperate for any information. Asgore stepped out and placed his hands on the railing.
Gaster looked at the Queen and sighed. He wanted to join the King but he didn't want Toriel to leave, and he didn't want her to hate him. He was torn between his two friends but he knew he had to stay by Asgore's side.
"Gaster, if he makes the announcement I think he will, I'm leaving. Come with me?" She placed a hand on his shoulder.
"I CAN'T. I WANT HUMANS DEAD TO, JUST NOT LIKE THIS. I WON'T BE LIKE THEM, I DON'T WANT TO HURT ANYONE WHO CAN'T FIGHT BACK BUT I DO WANT TO HURT HUMANS. I'D KILL THEM ALL, MYSELF IF I COULD. I JUST DON'T KNOW IF I HAVE IT IN ME TO HARM A CHILD."
She sighed, she knew she couldn't change his mind but maybe Gaster could change the King's mind. "Then promise me this... Take care of him for me and look for another way to open the barrier. Find a way for peace without bloodshed."
"THAT'S ONE BIG PROMISE, I'M NOT SURE I CAN KEEP IT BUT I WILL TRY."
Gaster looked at the Queen one last time before he to turned and joined the King on the balcony and stood on his right hand side. Asgore had just finished confirming the news that Asriel and Chara were dead.
"I will not let humanity's crimes go unpunished!" Asgore announced. "More humans will fall and when they do I will take their souls. We only need seven and once the barrier is down humanity will feel our wrath! We will all live on the surface in peace, our suffering will end! I will destroy humanity!"
The monsters below cheered in excitement and began chanting, "long live King Asgore!"
Although some began to ask questions and raise fears that if another war was started then they'd all be killed, after all humans were much stronger.
Gaster spoke out, he knew what would happen once Asgore had all the souls, he done a lot of research on them after all. "OUR REVENGE WILL COME FAST ONCE WE HAVE THE SOULS. ONCE ASGORE OR ANY OTHER BOSS MONSTER ABSORBS SEVEN HUMAN SOULS THEIR POWER WILL BE THAT OF A GOD. WE WILL NOT LOSE, I WILL MAKE SURE OF THAT. I'LL WORK HARDER TO MAKE SURE WE'RE STRONG ENOUGH TO WIN."
The monsters cheered again this time calling out Gaster's name as well as Asgore's.
"Long live King Asgore!"
"Long live the Great Dr Gaster!"
Gaster smirked at that, what a huge ego boost that was. He felt that it was rather appropriate after all he was pretty great.
The two friends stood together, Asgore's arm around Gaster's shoulders as they make promises of freedom to the people, giving them hope.
When they went back inside Toriel was no longer there, she'd really left. Gaster noticed that Asgore was close to tears. Gaster wasn't good with emotions, he never had been. His was a logical person, emotions were often times illogical but he couldn't let Asgore break down, not alone.
He hugged the King and he felt Asgore's strong arms wrap around his skinny frame as he cried. "Please don't leave me as well," Asgore sobbed out.
"I WON'T. I'LL DO ANYTHING TO HELP YOU. IF YOU WANT I CAN KILL THEM FOR YOU, I DON'T MIND."
"No, I am the King, it's my responsibility. I will not push it onto you, especially when I know for a fact that you don't want to. Please concentrate on your research. Make the improvements to The Core you were talking about, look into the barrier, do all the other work you have talked about. I'll do what I have to do."
"DON'T SUFFER ALONE, I'M HERE FOR YOU."
"Thank you, my friend," Asgore let go of Gaster and looked down at the ground. "I don't want to be alone, will you stay with me for tonight?"
"Of course, let's go to Grillby's. I think we both need a few drinks."
Asgore nodded weakly and he followed the Doctor out of the castle. They avoided as many people as they could on the long walk to Snowdin, they didn't talk much and when they reached Grillby's, he was closed. That didn't matter to them because Grillby let them in anyway. Grillby offered his condolences and he was pulled into a hug by Asgore. Asgore held the flame tightly in his arms for a few minutes before releasing him to let him go to the bar and begin to pour them all shots.
They didn't talk at all, the three of them were just sitting in the dark, empty bar, slowly getting drunk together in silence.