==This is an AU in which Caliborn/Calliope were raised by Dirk rather than Gamzee. Nonpost-apocalyptic setting with living Alpha bro. SFW==
Chapter 1
Had they not been so young they would have remembered first opening their eyes. The confusion and traumatic realization that the world around them was not void and black could have driven them insane could they comprehend what that meant. They were still fledgling, unaware that they were in fact separate beings condemned to one form. Everything was new and quaint, the new-found world waiting to be explored and probed with their raw and inexperienced senses. Their thoughts were conjoined, working as one to analyze the cascade of sensory-overwhelming information. Not too long after their awakening into this invigorating realm they were greeting by another creature. It was foreign to them, much like everything else, and it towered above on strange appendages that they did not yet possess in such infantile stages of life. Unaware of the potential danger looming they wriggled their way through the soil to acknowledge the being with figurative open arms. He took them in out of curiosity, they in turn accepting him as their parental figure.
They were indeed not human like their companion and caregiver. They had always questioned their irrefutable differences in appearance to the other, but never confronted their begetter on the subject. It had been years since their induction into his household and their distinct idiosyncrasies hadn't gone unnoticed. By now their personalities had divided, both announced themselves as independent entities complete with custom titles.
One was malicious and violent, spouting empty threats of slaughter and massacre. He was crude and rough although there was a tinge of compassion. He was fragile in reality, depending on negative response to fuel his contempt for the world around him. He found it difficult to adapt to the earth and its customs, never fully understanding the creature he had grown up with. His young mind was gullible, embracing superstitions that would otherwise be passed off as foolish and inconceivable to most. He always felt like they held truth; these childish beliefs were an escape from his putrid conception of the world. Magic and curses, hexes and sorcery; they were his fantasy, something he wished he could bring upon others in a hailstorm of wrath. He viewed himself as powerful and omniscient, believing that he could truly predict and control the actions of the humans. To him, he was the lord of ascendency and extermination. However egotistical his views of himself were, he was truly arrogant and childish in his aspect. He named himself Caliborn.
The other was polite and courteous, delightful to her human equivalent of a father. She was a model daughter but not without flaw. She very much had a temper when it came to her brother and those alike in mentality. She had retained the curiosity that was present in her infant stages, expanding her knowledge through printed material until her search inevitably brought her to the discovery of the internet. She became hopelessly involved in the idea of romance, similar to her brother but in a slightly different degree. She was enveloped with the countless fantasies laid out before her. The idea of love in it of itself fascinated her and she wished she could one day find "the one" as it was often described. She was the polar opposite of her brother yet in many ways synonymous. She named herself Calliope.
Dirk knew that he would be in for hell when he brought this creature into his home. He nursed it the best he could, surprised with what he learned about the carapaced monster with each passing day. He first truly realized their multiple personalities at around the age of two. They had begun to walk and talk, just like a human. Dirk tried his best to treat it as if it were his own, keeping himself open-minded in the sense that he never knew what to expect out of it. At this point he had named it Cal jr. after it's liking to his favorite bro: Lil' Cal. Dirk only recognized the tiny green alien as "it" because he had absolutely no clue how to tell this thing's fucking gender (although he had eventually defaulted to just using male pronouns).
The toddler had waddled up to him in the clothes that were hand crafted by the fashionable Dirk Strider. An orange onsie with plush smuppet rump printed over its entirety, it was a work of art, covered the alien presumably-boy. It's eyes were red at the moment, having the tendency to switch from aforementioned to green, they were large and needy. He tugged on Dirk's pant leg and was given no option other to give his new little pal attention.
"What's up little man?" Dirk stared down at the midget with a quirked eyebrow; he could feel the sharp claws grazing his skin as they poked through the fabric of his jeans. The alien stared up at him for a few moments, clutching Lil' Cal in his other fist by the arm. Without a word he bared his needlelike teeth at the taller man and lunged for his leg. He bit into the flesh, easily punching through the denim and instantly drawing blood. It welled into his mouth and the overwhelming metallic flavor coupled with Dirk's shrieking caused him to recoil, spitting and lagging out his tongue as if the blood was diseased.
Dirk pulled his leg back, tripping on himself and plummeting to the ground; he nearly hit his head on the kitchen counter with the fall. He was taken aback at this; he wasn't sure what to think. The toddler had just stood there, disgusted and distressed. He only stared at the child, gaping. Wait, was that kid smiling? Dirk's eyes darted from his wound to the cheeky bastard that stood rooted in front of him. It was smiling, it's face contorted into a twisted grin and the blood that was smeared across it's chin only gave it a very "The Omen" like feel. The kid was like Damien in his true form, Dirk was raising the anti-Christ.
He punished the kid the best he could without beating him. He wanted to be a decent parent in the least, not that a 15 year old could possibly make a good parent. He felt slightly guilty for consciously thinking of the kid as the anti-Christ. He couldn't hold him up the same standards as normal children; he was in fact a green skull-monster. So instead of holding a grudge he sent the kid off to bed, he would deal with it in the morning after he fixed himself up.
The next morning Dirk limped out of bed, exhausted after having a restless night due to the throbbing pain that insisted on keeping him up. He wasn't too much concerned with the pain as much as he was with the irritation it caused from slowing him down significantly. He poured himself a very shitty cup of coffee and was only beginning to feel its glorious caffeinated effects when he heard the clanking noise of claws on the hard wood floor. Dirk turned his head to greet the toddler as it smiled up at the significantly larger gentleman, again much like he did the night before except with a less malevolent undertone. His toothy grin soon fell into a frown when his now green eyes fell upon the bloodied wrappings.
He acted surprised as if he didn't remember what happened. He worried for his caregiver, offering the other hugs and kisses to make the boo-boo all better. The child's attitude always seemed to swing from one extreme to the other. One moment he would be biting and scratching and the next compassionate and caring. Dirk passed this off as some sort of alien mannerism before putting the pieces together in his head. That was the moment when Dirk understood that it wasn't a random mood swing but alternate personalities, each not having memories of the other's actions. It made sense, he assumed that the child simply was prone to memory loss or just didn't pay attention but it was in fact that it wasn't possible for them to remember when they hadn't been awake in the first place. They were individuals; they had different traits, opinions and even genders. Dirk found himself caring for twins all in one swift culmination.