Chapter 1 – Unfestivities

Author Notes:

- my own spin on making sense of the Adventure Time cast being present in FusionFall considering that even the creator said that the show takes place in a post-apocalyptic world. (A post-nuclear war if you pay attention to the hints in the show: An undetonated nuke in the opening, Mushroom War with emphasis on the "Mushroom" part, etc.) Anyway, enjoy your crappy fanfic.

- honestly, I'm not sure which category this should go in. Since the main story take place in FusionFall, I put it here. But the story is Adventure Time-centric so I considered the Adventure Time x FusionFall crossover category, but Adventure Time is already part of FusionFall canon so it seemed a bit redundant…

- Finn's going to be aged up to fourteen-years-old in this story


The Land of Ooo was in a relative mood of festive celebration, specifically the Candy Kingdom where the festivities would be soon taking place. In a few days would be the yearly Jewel Festival. Normally, the festival location cycles from kingdom to kingdom every year and this year was the Candy Kingdom's turn. The people were still in the process of setting up decorations and preparing the events so the streets were teaming with Candy People trying to reach their destinations.

The royal castle which stood at the center of the kingdom was in the same process of getting ready as well. Due to certain circumstances that had recently occurred, the princess was a little behind in preparations and had to enlist the aid of two well-known friends and adventurers of hers.

"Finn! I have an important task for you."

Princess Bubblegum had emerged from her royal chambers. The pair of adventurers, Finn the human and Jake the dog, was in the process of helping the candy princess decorate the interior of the entrance hall to the castle.

"Sure, PB." Finn said as he finished tying a banner into place. "What is it?"

"I need you to go find Marceline."

"Why? Something happen again between you two?"

"No. Nothing like that . . . Remember when the Ice King left a big mess in the castle courtyard and spilled my jewels all over it?"

"Hehe. Yeah. That was an awesome night . . ."

"Well, I think Marceline ended up taking an important jewel that I need for the ceremony in a few days. The Candy People told she was helping you clean up that day, right?"

"Yeah. She was just returning a favor she owed me."

"I see. Well, just make sure you bring the jewel back. I really need it if I want this ceremony to go well."

"You can count on us!" Finn exclaimed. "C'mon, Jake!"

With Jake quickly following behind him, Finn dashed out the front gates and into the candy-paved streets. The duo happily zoomed past many familiar faces along the way, greeting each of them by name before eventually running across the drawbridge outside the kingdom's protective walls and down the only dirt road.

"Hey, Finn." said Jake. "Shouldn't we be cutting through the forest? I mean, it'll be much faster."

"I know. But I wanna stop by our treehouse first. I have to show Marceline that new sword we got from rescuing that old guy from those trolls."

"Oh yeah. Those trolls just wouldn't leave him alone. Good thing we found some troll spray."

Once they arrived at their treehouse home, Jake waited outside while Finn quickly ran inside to fetch the sword he mentioned earlier. It was taking quite some time so Jake ended up playing with Beemo, their sentient videogame console, for about fifteen minutes.

"I found it!" Finn exclaimed as he burst through the front door. He was now holding a glowing blue sword in his hand. It seemed to be extremely high-tech, futuristic-like.

"Where do you think that guy found that sword?" Jake wondered aloud.

"Don't know. Bought it or earned it, maybe? There's a worn out logo on here, but it's barely readable . . . 'Dex' . . . 'Labs'. What you think it means."

"Hmm . . . 'Dexterous Labradors'?"

"Nah. I don't think so. Anyway, let's go see Marceline."

Marceline the Vampire Queen was known to have multiple living places, but she seemed to spend most of her time in her regular pink house located in the depths of a dark cave so the duo headed there. Finn knocked on the front door and found Marceline answering in a few seconds.

"Oh. Hey, Finn." she kindly greeted him, letting the two inside. She seemed to have been practicing her bass-converted family battleaxe. "You need something?"

"Yeah. Uh, Princess Bubblegum sent me."

"Bonnie? What does she want?"

"Remember when you were helping me clean up those jewels the Ice King spilled all over the castle's courtyard? Well, PB said you might've accidentally taken an important jewel by mistake."

"What? No. I gave back every single one I found. I even triple-checked all my pockets and anywhere else they could've gotten stuck."

Finn knew Marceline was telling the truth, but now he was curious about what happened to the stolen jewel. If Marceline didn't have it, who did? A passing by Candy Citizen? A mysterious thief?

"Then I wonder where that jewel is . . ." he muttered to himself.

"Hey, Finn!" a voice exclaimed from outside.

Finn and the others went outside to find Princess Bubblegum awaiting them. She was riding on the back of her trusty rainbow steed and Jake's girlfriend, Lady Rainicorn.

"I found the jewel about twenty minutes after you left." Princess Bubblegum informed them embarrassed. "I'm sorry to have wasted your time, guys."

"You wasting time? Big shocker." Marceline sarcastically remarked. "Anyway, what else do you want? If you brought Rainicorn here instead of your swan or marrow then there's definitely something else."

"Oh, well . . . I kinda need to borrow back that brush I gave you. Lady Rainicorn here simply refuses to have her mane brushed by a normal brush for formal events this huge and I seem to have misplaced my spare . . ."

Marceline sighed. "Fine. But, uh . . . I don't have it . . . anymore . . ."

"What! Of all people, how could you lose it!"

"Hey! It's not my fault! The Ice King stole it! Plus I never thought you'd actually want it back someday."

"Why. Did. He. Take. It?" she angrily asked.

"I think Ice King was kinda sick of having Finn and Jake show up and beat him up when capturing princesses so he tried having a go at queens. I think you can figure out things from there."

"Go on . . ."

"Well, he broke into my house while I was gone and I came back to find him rifling through my drawers. I chased him out, but he ran off with the brush. I think I heard him say he was gonna use it to groom his beard."

"Oh yeah!" Finn exclaimed as he remembered something. "I think I saw it when we were rescuing Breakfast and Toast princess the other day."

"Yeah. It fell on the Ice King's head and onto the ground when we shoved his face into his toilet." Jake laughingly added.

"The Ice Kingdom's close to here. You could just wait here while Jake and I get it for you."

Princess Bubblegum and Marceline awkwardly twiddled their own fingers at the suggestion.

"Uh, Finn." Princess Bubblegum began. "I don't think that's such a good ide-"

"Why don't we just go with you?" Marceline interrupted. "We can just distract the Ice King while Bonnie and Lady Rainicorn go for the brush."

"But I don't have my winter coat . . ."

Marceline sighed. "Here. You can borrow one of my old ones. What size were you again?"

Princess Bubblegum followed Marceline to another room of the house while the others waited outside. Jake began chatting with Lady Rainicorn about recent events and about the times they were away from each other. Finn really couldn't join in on the conversation considering that Lady Rainicorn spoke a language he didn't understand and would have to constantly bother Jake for a translation. The only universal translator they found was also broken as well. Instead, he sat upon a nearby rock, closely examining his new sword more thoroughly. The longer he looked at it, the more he wanted to learn of it capabilities.

Seeing as how the two females would take some time, Finn began practicing on the nearby boulders and stalagmites. The sword didn't seem to be imbued with magic properties like sharpness enhancement since the blade couldn't cut through solid rock. Finn tried pressing all the small buttons he could find on it, but they had no effect. Despite that this was basically a regular sword though Finn did admit that the glowing blue outlines on the blade gave it a cool factor.

"Alright, I'm ready!" Princess Bubblegum exclaimed as she emerged from the house. She was now wearing a pink winter jacket and a pair of the same colored pants (albeit a darker shade). "I was wondering where I left this. I've been searching for it forever."

Marceline didn't change at all though considering she was a vampire, it didn't really matter, but she did bring her umbrella to protect herself from the sun's rays. "Can we go now?" she asked.

"Sure." Finn replied. "Princess. Me, Jake, and Marceline will distract the Ice King. Once we get him into another room, go in though the window and towards the bathroom. When you have the brush, give us a holler and make a break for it."

Using his shapeshifting powers, Jake grew to a gigantic size as he exited the cave. Finn climbed above and sat upon his head. To his left was Marceline flying alongside them and to his right was Princess Bubblegum riding on Lady Rainicorn.

It took some time, but the group finally arrived at the borders of the Ice Kingdom. Marceline was able to retract and put away her umbrella now that the sun was now being blocked by the clouds. Judging by the darkness slowly progressing snowfall and wind, there seemed to be an ice storm brewing.

"Let's make this quick, guys." Finn said as he put on his yellow sweater.

Jake lowered Finn before shrinking down to normal size. Trying to add some quality of fun to this adventure, the two along with Marceline each grabbed a nearby penguin waddling nearby and used him as a sled down the slippery slopes of snow. Princess Bubblegum and Lady Rainicorn simply followed along from the skies though Marceline did tease the princess for not joining in on the fun.

After swerving across many hills and around a few mountains, the group came to the entrance to the Ice King's palace. The ice ramp to the front door doubled as a slide so it was difficult to climb without assistance. Finn and Jake took the easy way out and used the latter's powers to reach the large window at the side of the palace. Princess Bubblegum waited outside, using Lady Rainicorn's mane to help keep her warm.

Finn and Marceline took the first peek to find the room empty. They quietly proceeded inside and checked both exits for signs of the Ice King. Nothing. Finn went back to give the clear signal to Princess Bubblegum as Jake and Marceline went on ahead.

Finn was assisting the princess as she stepped onto the windowsill and into the room. The young boy couldn't help but blush. This would've been a little embarrassing had the princess noticed, but her eyes suddenly widened before she had the opportunity.

"Finn! Look out!"

Princess Bubblegum pushed Finn aside and hurled herself onto the floor to dodge an incoming ice bolt. The princess had reacted just in time, only letting a tiny portion of her bubblegum hair to be scraped. Lady Rainicorn wasn't as lucky as her tail suffered a direct hit, completely encasing it in ice and causing her to run away.

"Ice King!" Finn exclaimed as he drew his sword.

The Ice King, a short, blue, pointy-nosed, elderly man dressed in a dark blue tunic with a large beard was angrily standing under the doorway connecting another room. His hands glowed bright blue to signify his ice powers. Their aura was quite intense so the Ice King was clearly furious.

"What are you two doing here!" the Ice King exclaimed. "Today's the day I get to spend some time writing my fanfiction and this is the day you actually bring me a princess! Argh!"

The Ice King fired multiple ice bolts towards the two, but Finn managed to block and reflect each one although none of them actually rebounded onto the Ice King.

"Princess! Run!"

Princess Bubblegum nodded as she made a break for the nearby hallway.

"Oh, no you don't!" the Ice King exclaimed. He quickly formed an ice wall between Finn and the princess and fired another ice bolt. "Gotcha!"

The princess didn't have enough time to move. Knowing it was useless, she simply awaited the bolt to hit and freeze her. Then suddenly, the bolt was deflected by a blood-red battleaxe. Marceline and Jake had just showed up having heard the previous angry rants from the Ice King.

"You owe me big time, Bonnie." Marceline teasingly told her.

"What! There's two more!" the Ice King exclaimed. "Grr! Where's Gunter when you need him!"

Jake took Princess Bubblegum along to find some safety as Finn and Marceline engaged the Ice King in combat. They merely exchanged blows back and forth, but barely any of them made direct hits. After a few minutes, the fight was suddenly interrupted by a loud, high-pitched scream.

"Princess!" Finn exclaimed.

The Ice King took advantage of this unexpected opening and encased Finn and Marceline in a block of ice, only leaving their heads unfrozen.

"Hehehe. Got you now." the Ice King said aloud.

"Ice King! The princess is in danger and you're more worried about us!"

"Why should I care? There's plenty more where they came from."

"Something's not right." Marceline observed. "Ice King would never say that . . . Finn! Look at his crown!"

"What? . . . Holy stuff! The jewels are like gooey green! He's not in control of himself!"

"Whoever's behind this must've found Bonnie."

"We have to knock off that crown!"

"Leave it to me~."

Using her own shapeshifting abilities, Marceline slowly grew and transformed into a monstrous form of herself, shattering the ice prison in the process. She then turned into a small vampire bat and flew towards the Ice King at astonishing speed. The man tried shooting her down, but she dodged every attempt. Once close enough, Marceline grabbed the crown by her feet and tossed it to the floor with Finn retrieving it. Since the crown contained stolen ice powers, the Ice King was rendered powerless and fell unconscious.

Now that there was no longer an obstacle hindering them, Finn and Marceline hurried to meet up with Jake and Princess Bubblegum. They followed the screams and cries for help to the foyer of the palace.

"Princess! We're here to save yo-Holy shmow!"

Finn and Marceline came to find Jake trying to battle a strange demonic creature who seemed to wield fire as an element. Whatever he was, he was humanoid in shape and had the ability to levitate. His skin was pure black as night. His thorax, abdomen, and pelvis completely consisted of nothing but small skulls. He wore a flowing cape that was black on the outside and bright green on the inside. The creature gave a menacing smile at Finn and Marceline as they entered. The only indication of a face was its green mouth and burning green eyes. His fire-like hair was flowing intensely.

"Ah, so you defeated that pitiful excuse for a so-called 'Ice King'." he remarked in a high-pitched voice. "No matter. More people means more fun!"

"Marceline." Finn said. "Do you know what that is?"

"I've never seen or heard of anything like that my entire life." she replied.

"Oh, well. Let's just go help the princess!"

Finn drew his sword and charged forward. The creature laughed at this, what he considered, feeble attempt. He simply flew back and hurled a barrage of fireballs at the boy. Now used to the movement from the previous fight, Finn blocked every shot and continued approaching him.

"Hm. You're much more competent and able fighter than the dog and old man." the creature said. "Seems like you've forced me to utilize more of my power~!"

The creature grabbed two skulls from his body and tossed them towards Finn, but he was able to easily dodge it.

"Ha! You missed me!"

"Such ignorance." the creature said in an annoyed tone. "Those are not my weapons." Finn was confused, but then he looked back to see the skulls shaking and breaking open. "Thoseare my weapons!"

Once shattered, the skulls radiated a blinding light. When it subsided, standing in their place were two large creatures of unknown origin, not any creature found in Ooo. They were both humanoid. One was similar to a magma golem. It was humanoid in shape and its body was made of red and brown rocks due to the molten magma contained in its body. Its head was burning aflame like a torch. The mere presence of its heat was enough to begin slowly melting the interior of the foyer. The other creature was shorter in stature, but that was due to being hunched over. Also of a humanoid shape, its skin was bright blue and thin black armor covered its body. A helmet masked his face and what seemed like feet were small wheels.

"Kill them." the demonic creature happily ordered.

The magma creature produced a flamethrower from each hand and fired them at Princess Bubblegum and Jake. Having no defense against fire, Jake scooped up the princess and avoided the attack by stretch his legs to raise his body. Meanwhile, the blue creature dashed towards Finn at astonishing speed. Logically, it shouldn't have been able to do this due to the icy floor, but its master seemed to have cast a spell on its feet, indicated by the green glow. It knocked Finn over before he had the chance to counter. Marceline tried to help, but she ended up suffering the same result. All the while, the demonic creature was still laughing.

"By the way," he said, "I guess you have the right to know that I'm Demongo, the soul collector. The ones you're fighting are the essence of the warriors I've defeated. If you lose, you'll become the newest member of my collection! Ahahaha!"

"Finn!" Jake exclaimed as he stretched his limbs to avoid another fireball. "Me and PB could sure use some help over here!"

The plea was useless. The blue creature kept on intercepting Finn and Marceline and knocking them back, even if they went in different directions at the same time. The magma creature soon cornered Jake by summoning two firewalls. The resulting water made Jake lose his balance and topple over with a splash. The firewalls walls then began to close in with no way to escape.

"Finn!"

In almost a split second, the entire room's temperature dropped to below freezing level. A storm breeze of snow swept by, extinguishing the fire and refreezing the water. Confused by this sudden change, the magma creature tried igniting another fire, but was immediately encased in a block of ice cold enough to extinguish its flames. As a result, its body poofed into a cloud of green smoke and flowed back inside Demongo's body.

Standing by the doorway was the Ice King, having regained consciousness, wearing his regular crown again and back to his normal self.

"You! No one makes a fool outta me and gets away with it! Especially for attempting to harm my future wife and those two boys!"

"Hey. What about me?" Marceline angrily questioned.

"Eh? Oh, uh . . . do I know you? I don't think we've talked to each other much . . ."

"Enough of this insolent banter!" Demongo exclaimed. "Though I must admit, you seem much more competent when provoked. It was enough to defeat my Pyronite. I like that!"

"Yeah, yeah, yeah." the Ice King remarked. "Just get out of my castle!"

The Ice King fired his endless barrage of ice bolts towards Demongo who countered with his fireballs. Now that the enemy was distracted, Jake assisted Princess Bubblegum to her feet and went to help out Finn and Marceline. Using his own stretching limbs as a trap, Jake captured the blue creature now struggling to break free. Finn and Marceline then dealt the finishing blow with their respective weapons. Like before, the creature turned into smoke and flowed back to Demongo's body.

No longer occupied by another enemy, everyone focused their efforts on Demongo. (except Princess Bubblegum who cheered them on) Despite being a powerful being, Demongo couldn't handle this many opponents at once. He couldn't summon his essence warriors either now that the Ice King could freeze the skull containers before they even opened. Eventually, he was overwhelmed and knocked to the floor by a punch from Jake.

"Insolent worms!" he said panting. "My lord will surely have the last laugh! . . . Though my mission here is done anyway. I was merely a distraction! Farewell!"

Demongo slowly arose and drew a strange large green gem hidden inside his cape. He laughed as it grew brighter each second and began levitating by itself.

"I sure hope you enjoy your destination!" Demongo exclaimed as he disappeared in a cloud of smoke.

The entire palace began shaking tremendously. Gigantic icicles hanging from the ceiling broke off and rained down, forcing everyone to scramble for their lives.

"Bonnie! Look out!" Marceline exclaimed as she pulled Princess Bubblegum away from a falling icicle.

The force of the impact was enough to shatter the floor and send everyone falling into the dungeons. Marceline, who was still holding onto the princess, and the Ice King could fly so they had nothing to worry about and Jake was able to act as Finn's cushion.

"We have to get out of here!" Princess Bubblegum exclaimed.

"We can't!" the Ice King responded. "The only way out is up and there's giant falling blocks of ice everywhere!"

The earthquake continued to grow even worse. It got to the point where the foundations of the palace could no longer take the intensity and broke apart, sending everyone plummeting straight into a strange wormhole that had appeared directly under the palace.