Landing into a patch of vines, our main character wakes up and glances at her surroundings. The patch of vines, cushioning her fall, and she picked itself up from the ground. By the ground, lay a stick, which it took as a weapon. And she staggered, to look upwards, into the beautiful sun and the clouds surrounding it. She asks a question," Where am I?" And looked around to see a vine, just sitting there. As she approaches the vine, the vine suddenly began talking.
"Hello! I'm Viney the Vine. You seemed to be confused about where you are. Let me help you. You are in OOO, a wonderful place to be. Let me explain to you something, my vines would help you in OOO, come touch them." Viney offered, and vines started growing near it, it jumped to the side, frightened by what it is seeing. It instead, whacked the vines with the stick, causing some movement from Viney. "You piece of shit." Viney growled, and wines appeared from the ground, surrounding her.
"My name is Chara, not some piece of shit!" Chara declared, using the stick to fend herself from the barrage of vines until Viney and his vines disappeared. Chara gripped the stick determined to finish off Viney until flying female approaches.
"Good day. I see you are here fixing what remains of Bonnibel's experiment." She started and rolled her eyes. Chara studied her with renewed interests. "My name is Marceline, and here is a phone if you need to text me if anything happens. I'm off to handle some affairs, so goodbye." She bid her goodbye, flying off, and Chara sees a cave nearby. She kept the phone in her pocket and gripped the stick, prepared to kill if necessary. Her first opponent, a vine. It approaches her, it just observed her. Chara smiled and whacked it with her stick, doing a lot of damage to the defenseless vine. It began fighting, though, vines began appearing from the ground, and she jumped about dodging them, and she finished it with a blow. Turning it into pulp, before into dust. She grabbed the dust and rubbed her body with it, her arms and her legs. She feels the power flowing into her and wants more and more. She grabbed the remaining in hr hands, with the stick, the dust that empowered her was gone, and now she wanted more. She whipped her stick, ready to kill.
After killing multiple organisms outside the cave, the cave had more organisms in it. Bats, rats, cockroaches, all kinds of stuff that require killing. She killed them one by one, gaining more dust, getting more LOVE, which she loved to get more. She found a house in the cave, and opened the door, to see the flying lady known as Marceline chilling on her couch. "What are you doing here sweetheart?" She glanced at Chara, who gripped on her stick. "You don't mind if I suck your blood?" Marceline grinned evilly and the two began combat. Marceline was just flying about, ignoring Chara. Chara, without words, attacked. She did minimal damage, but it is still damage. "Oh, this is going to be fun!" Marceline declared, and she morphed into a giant bat and began pounding on Chara. Chara dodged the attacks with ease, swiping with her knife on her arms and legs. Marceline laughed again, and they began wrestling, Marceline pinned Chara down in her normal form, but Chara brutally kicked her away, jumping up, to kick her opponent down. Which is what she did, she kicked Marceline down on the ground a few times, but Marceline countered by grabbed her feet and slamming her on the ground. Chara moaned in pain, before focusing on combat, the two traded blows with one another. Punching each other, pushing each other, flinging each other away. Chara sees a base guitar on the wall, she grabbed it and brought it down on Marceline began bleeding, but her wounds quickly recovered, Chara gritted her teeth, continued her assault. Marceline took her hits but was not affected in any way by it. "I'm a vampire, you got to stake me, but you cannot. Might as well let me suck your blood." Chara studied her opponent she seemed to be sparing her, but this was her opportunity. She grabbed the axe base and her stick and sharpened the stick with the sharp edges of the base. Marceline face was filled with curiosity, but after Chara was done, her face was filled with horror. "What are you doing with that stick?" She asked, and Chara lunged, to plunge it into Marceline, killing her. Marceline lay on the ground, gasping for breath, and said her final words. "Tell Bonnibel I loved her still." Marceline reached her hand out, stroking Chara's chin and turned into dust, which Chara greedily grabbed, powering herself. She got out of Marceline base, using her base as a weapon instead of her stake, but she took it with her, just in case there are any more vampires to be staked, in which she will gladly do. She stepped out the cave, and sees a boy and a dog, they were having fun, playing in the grass. She grabbed the axe base and walked towards them.
"Hey there!" Finn called out. Jake looked at the direction Finn was looking, they see a girl holding a base covered in dust, but it sure looked like Marceline's old base. She had a new one, after trading the treehouse for the cool new base.
"Marceline giving away bases, unbelievable." Jake remarked, but the girl walked towards them.
"Hi! I'm Finn, and you are?" Finn stretched out his hand, expecting for her to shake it, but she brought the axe base down on his metallic arm, and she reeled back in the shockwaves caused by the blow. "I take that as an accident. This is my dog Jake and you are?"
Chara decided to play along, it seems that the boy and the dog are better fighters than her, she had to play with them and get more dust on the journey before killing the two. "My name is Chara, and I cannot wait to kill you two." Chara truthfully said, and the two laughed, belittling her.
"Where are you from Chara?" Finn asked, but Chara shook her head.
"Tell me. How do I get out of this place?" Chara asked, wanting to get the hell out of OOO.
"Oh, very simple. You just have to steal the gems on the crowns of the princesses and put it in the enchiridion." Jake remarked before Finn covered his mouth, weakly smiling. By that time, however, Chara had already walked off, to the nearest kingdom. There were pink trees surrounding the kingdom.
"Dude! She's going to the Candy Kingdom!" Finn exclaimed and Finn ran after her, leaving Jake behind. Jake walked behind a tree and disappeared.
Chara went on a killing spree in the Candy Kingdom, cutting down the Banana Guard, which invited more, to be killed also. As a small Candy Kid ran over, she hacked him down, and he fell, turning into dust. She smiled, gripping more dust, the Gumball Guardians fired their lasers at her and she jumped out of the way and chased after a Gumball Guardian. She stabbed the base into the Gumball Guardians leg, then repeating it again and again, with each swing, the higher she went. The other Gumball Guardian stupidly fired its laser on his friend, taking him down. The Gumball Guardian fell to the ground, the shards killing the Candy Citizens around him. Chara smiled, admiring the dust appearing everywhere. She fell to the ground with a thud, but the dust empowered her, and she picked herself up, unscathed from the chaos. The Candy Citizens ran for their lives, and she cut them all down. A sound of a rattle ball caught her attention and a robot with a sword leaped from the roofs to engage her. The thing whipped out his sword and she caught the blow with the axe. She smashed the robot into pieces with the axe and grinned imply. She sees the sword, much lighter and flexible than the axe, she threw the axe aside and decided to use the sword instead. She picked it up and was able to see her own reflection on the sword. She smiled and looked in front of her, the castle, where there would be a princess whose gem must be stolen, although she prefers the other way around.
After multiple killings, she kicked opened the bedroom door, and sees a princess, looking over the balcony studying the scene happening around her. Blasts of laser were fired upon Chara and she dodged them all easily, it was as simple as the last world she conquered, except that skeleton. Chara lunged forward and hacked off Princess Bubblegum's arm, which fell to the floor. Princess Bubblegum face turned to horror, as Chara repeatedly hacked Princess Bubblegum to bits. Her fingers, legs, and arms were laying everywhere, as she waited. They finally turned to dust. And she smiled, she gripped more dust, powering herself further. She sees Princess Bubblegum's laser pistol with a holster. She wore the holster, and slid the laser pistol in the holster, she searched the castle. The kitchen had a few knives. She grabbed the knives and strapped them to her chest. There were many useful things in Princess Bubblegum's room, and she had many straps to hold weapons with for some reason. But Chara took it anyway and left the castle. The Candy Kingdom was empty, dust lay about, and bodies that have not turned to dust lay about. Screams of pain and help can be heard but were quickly silenced. Chara looked back to see the carnage she caused, only to turn around and head on.
"Holy shit!" Jake remarked, seeing the dead bodies by the gates of the city, and dust lay about, there was also lots of red liquid around the city. Banana Guards sprawled all over the ground, knife marks entrenched on their bodies, flies flying all over the corpses, intent on having a feast. Finn and Jake just stood there, unsure of what to do.
Finn angrily punched the ground with his metallic arm, which did not hurt. "We could have stopped her earlier!" Finn screamed.
"Let's check on Princess Bubblegum. She may have escaped all this carnage, she is smart." Jake remarked, and Finn nodded. They searched the Candy Castle, in her bedroom, was what remains of her body. The two took off their hats in respect, and they turned around, prepared to leave her in peace when a door appeared from the wall.
"What you doing here guys, we got a killer to stop!" Princess Bubblegum declared, she was dressed in a black coat, and a fedora, strapped along her coat, were a large array of weapons, mini bazookas, huge bazookas, rifles, pistols, shotguns, snipers, you name it, she had it. In her hand, she gripped a revolver, and in the other, a grenade.
"Shit just got real." Jake thought.
Note: Jake used to be part of the mafia, so I'm giving him all the roles where he needs to swear in. This is Chara, the one from Undertale, who have just destroyed the world, and now out to destroy another. This is after the finale of Season 7 and somewhat after that, Finn has a metallic arm.