A/N:
Major trigger warnings. If you don't like violence, don't read italics.
Italics are flashbacks/dreams.

Ella had chained the leviathan, still wearing her father's face, to the chair before pulling out one of her ruined blades from her bra.
The creature laughed maliciously at the action, "You think that tooth picks gonna do anything to me? You're way out of your depth, girl."
Ella smiled, reaching for the cleaning product she swiped from the cabin, pouring it over the knife. She brought it up to the monsters face, allowing some of the liquid to drip onto its cheeks, causing it to groan in pain, before cutting a line across its uninjured cheek.
The monster gritted its teeth, a small cry escaping.
Ella dipped her knife in the borax again, colouring the clear liquid with the black blood on the blade.
Her father's blue eyes narrowed as she brought the dagger back towards the creature.
"It's gonna take more than that, bitch." It spat.
Ella nodded.
"Though it might." She replied, her voice soft, before stabbing the leviathan in the stomach.
The creature screamed, breathing rapidly.
"Where's my Dad?"
It growled at her.
She pulled the knife out, soaking it in borax before stabbing the creature again.
"BITCH!"
"Where's my Dad?"
The face that was so familiar to her, now dripping with sweat and black blood, smiled cruelly.
"Dead. He tasted mighty fine."
Ella shook her head, "Where's my Dad?"
"DEAD!" The leviathan spat.
Ela brought the borax soaked blade down on one of the creatures fingers, severing it neatly.
The creature cried out sharply.
"Where's my Dad?"
"HE'S DEAD!"
Ella, breathing raggedly, picked up the remaining borax.
She grabbed its face, forcing its jaw open before pouring half the bottle down its throat.
It screamed.
Ella winced at the sound of her father's screams, but continued knowing this thing was the reason she would never see her father again.
"Why are you in Australia?"
The leviathan gasped for breath, its insides burning.
"Why are you in Australia?"
The creature continued to writher in pain, its skin beginning to blister from the inside.
Ella held her stolen machete to its throat.
"I can make it stop. I can make the pain stop. Why are you in Australia and where is my Dad?"
"He-he's dead. He got too c-close to base camp. He w-was working it out. We couldn't let the hu-hunters find out what was happening." The leviathan gasped for air, tear streaming down its face as it grit its teeth.
"Why are you in Australia?" Ella asked holding the borax above the leviathan, threateningly.
It withered and shied away, trying to escape its bounds while still gasping for breath.
"We needed somewhere isolated, but with a large population. Australia has the second worst urban-"He paused, panting,"-urban sprawl in the world and we needed to be sure rural communities would be infected as well. We can't have anyone fighting the system."
"But why k-kill my Dad? And why not use a rural part of America?" Ella asked, her voice breaking.
"The hunters are getting in the way, and we couldn't risk them warning the general population. Your father stumbled across the base camp, he figured out what was going on and he was going to tell the other hunters. He needed to be stopped, and so did you."
Ella nodded slowly, absorbing and memorising all that she had been told. It made sense.
"Where's your base camp?"
The creature shook its head.
"Tell me."
"N-no."
"Tell me."
"NO."
Ella grabbed its face, using her knife to drip borax into its eyes. It thrashed and withered, screaming in pain.
"CANBERRA!" It gasped in pain, blinking rapidly, "The ACT. Your dad was going to tell everyone where it was."
Ella griped the stolen machete tighter, it was more than likely that the leviathan was lying but she'd promised to end its suffering. And Campbells kept their promises.
She swung the blade hard, decapitating the creature neatly.
Knowing it wasn't really dead, and what would happen if she left it there, Ella picked up the severed head before praying to Cas.
He appeared, grasping her shoulder and teleporting them back to the cabin.

Ella sat up slowly, her head aching, and looked around the quiet room, noticing Jake slumped in a chair at the door. She'd been carried to one of the two beds in the bedroom, and a glass of water had been left for her on the small and rickety bedside table. She reached for it now, sipping it slowly.
Her stomach rumbled, aching dully in hunger.
She swung her legs over the side of the small bed and stood up, her head spinning as soon as she did. Ella sat down quickly, the bed creaking, not trusting herself to walk.
Jake stirred at the noise, gently opening his eyes, sitting bolt upright when he saw Ella awake.
"Ella!" He cried, walking quickly to the bed and holding his hand to her forehead.
"Do you feel okay? The angel said you fainted because of low blood sugar and dehydration. You need to eat something sugary, right now." Jake said in a rush, grabbing the nearly empty glass and rushing to the kitchen.
Ella laid back, chuckling at Jake's concern, as she listened to Jake taking to Sam and Dean.
"Do you have anything sugary? She needs sugar." Jake asked, rushing around anxiously.
"Perfect!" He cried, before rushing into the bedroom with several donuts.
Ella sat up carefully, chewing each donut slowly and feeling the hungry ache in her stomach slowly subside.
Jake stared at her anxiously the entire time, and she smiled at him reassuringly. "I'm fine, Jake. Just hungry."
Jake raised an eyebrow, "You're fine are you? That's good, because I'm not. You could've been KILLED! I wake up and you've disappeared with the FUCKING ANGEL and decided to go on a HUNT by YOURSELF! I THOUGHT YOU WERE DEAD!" He shouted, standing and walking towards her threateningly.
Ella shrank back, eyes widening at his anger.
Jake leaned towards her, fists clenched, before pulling her into a fierce hug.
"I'm sorry I scared you, Jake." Ella said softly, Jake just sighed in response, pulling back gently and kissing Ella on the forehead.
"Get some rest."
"I can't. The leviathan-"
"-Is dead. Take a break."
"But they're planning on using Australia as a test run for the American invasion. I need to talk to Sam and Dean. It's really important."
Jake clenched his jaw, before nodding slowly. "I'll go get them."
Ella shook her head, "It's fine, I can walk."
"No. You need your rest. If you want to talk to them, they'll come to you." Jake said in his no nonsense tone before fetching the Winchesters.
Ella laid back and waited for them to return.

A/N:
Sorry for anyone who doesn't like my terribly written torture scene, but it was necessary for the info dump. ;)
Much love to Isabella for helping me edit and explain away my plot holes.
THANKS FOR READING! ;)