It is in their eyes that their magic resides.
-Arthur Symons
The summons was abrupt and instantaneous. One moment she drifted along the spirit paths, the next she coalesced, invisible, above the ritual site. An invocation was more common, a gentler request that left the response at her discretion. Even for her, it had been a long time since she had last been summoned.
A growl reverberated in her throat, unheard by any of the corporeal beings below. Her thwarted slaver was distracted, defending himself against the human girl. The Shadowmen's Huntress, she realized, and identified the Shadowman off to the side, watching the battle. They had existed long enough, were prominent enough in supernatural circles that she knew of them, though had very rarely interacted.
She snorted silently. It was pragmatic, she supposed, that the Shadowman focused his attention on the threat rather than the summoning circle. But though she could not lay claim to human emotions or morality, she was not unaffected by the sight of thirteen slowly dying human newborns. It was sad, and a waste of such potential. If she could have chosen the steps of the ritual, the sacrifice required, this would not have been it.
She prowled, tail lashing as she tested her bonds. The ritual had been interrupted. Just in time to prevent her enslavement to the warlock, but not in time to stop it completely. The contract had been outlined. It could not be void or canceled, and there was no use trying with the lifeforce of the newborns slowly but surely trickling away.
She could, however, alter it.
She could choose. She didn't have to be a voiceless weapon this time.
But she needed to decide quickly, before the warlock died and the Shadowman could turn his attention to the ritual. She had no doubt that they would take her or her chosen host and turn her into the weapon the warlock had hoped for.
This time, when she turned her attention to the newborns, she looked beyond their fading lifeforce and saw their potential. Where they had come from and everything they could be. That was, after all, what the sacrifice centered around: thirteen babies, thirteen days old, with the greatest potential. The power fueled by that potential cut short was powerful enough to bind even her.
She wasn't quite sure what she was looking for as she drifted closer to them. Some were silent, while others gasped or softly whimpered. Some were absolutely still, others weakly twitched their limbs. None seemed strong enough to contain her, no matter how gently she could coax the magic, or how willing she was to protect her host.
One might. His will to survive shone bright and drew her closer. This male, new as he was, struggled mightily for such a tiny thing. Not outwardly, but his spirit was powerful. It might be enough to contain her. Her presence might be enough that his heart would continue to beat.
She allowed the ritual to funnel her into his soul. He whimpered and moved restlessly, like the rest too weak to scream or thrash. It was done in an instant, just before the warlock was killed. Before the Shadowman turned his attention to the one babe to survive, before the chaos of other humans appeared to bundle the boy away.
She settled, curled up unnoticed within the newborn, beyond what magics could sense.
He was her charge now.
This idea first came to me when I was rereading the Naruto fanfic "She Likes Bugs" by fringeperson, while I was on a Criminal Minds/Buffy crossover kick. Mostly it was the characterization and personality of the Kyuubi, because this fic barely resembles that one, and only if you squint. Plus, I barely mention the Buffy universe aside from maybe setting; a few characters may be referenced much later in the story, but they are unlikely to actually be seen. This idea just sort of evolved and mutated over the months, or possibly years.
This will be a drabblefic, partly because I think it works best that way, and partly to see if I can trick myself into updating more often. It will cover Spencer's life from childhood through a number of the show's seasons.