Happy birthday, Dementian!
The infant's eyes were befuddling: When they were not glistening with distress, they shone with uncanny radiance, and that raw emotion gripped Hiei in a very peculiar way, a way he had never really let anything grip him before.
Neither he nor she knew what it meant to nurture.
Maybe that was the cause of his wariness. No matter what is or what would be, he and Mukuro would always be of a different breed than it was. The child was free to feel what had long been sealed by lock and chain inside of Hiei, sealed for so long that it had decayed into nothingness, its remains that of rust and the glistening fibers of heartstrings stretched so far and so quickly they could have done nothing but snap. It was sharp - so sharp that it pained him, and whenever the pain became a dense numbness inside his chest, he was forced to wonder whether it had even existed at all.
It cried. It cried to be held or fed or because he had spoken crossly. It giggled and squealed with delight whenever Hiei nuzzled their faces together and errant strands of his hair tickled its skin. It had little reason to worry. And maybe that was ironic. Or maybe it was the way Mukuro stared at it, fear glinting in her good eye like flying sparks from the blades of clashing swords. It was as though she had never been more at a loss in her life than when the child she held in her arms reached for her face with its chubby little fingers, so hopeful and affectionate. How unbelievable that it wouldn't realize what her arms had engaged in, the countless deaths they had caused, couldn't fathom the blood or the agony.
Hiei often wondered if its apparent fondness for him might be some proof of the goodness he wished he possessed. But if it saw too deep, that could only be cause for concern, for he was certain that if anyone were able twist something so innocent as this into a dark, confused mess, it would be him or it would be her.
But, no - this creature was simple. It could not, he convinced himself, be tainted by the two of them. Love was love - it did not matter who it came from - and perhaps he cared for this child enough to classify the blossoming feeling in his heart as love. So he would endure the messes and the crying, and he would allow himself to relish the moments when the infant lay atop his chest, limbs splayed, and he could bask in the sensations of its tiny body and the warmth of Mukuro's breath on his neck as they slept.