The eye Kikimora reveals when she lifts that one hair-finger has a red sclera, yellow iris, and black pupil. Black on Yellow on Red.
The sky during the Day of Unity's eclipse is mostly red, but the eclipse itself is a black dot in a yellow corona. Black on Yellow on Red.
In both cases, the spell attacks a person (in this case Raine) via their coven sigil, and they even have similar effects, with sprawling veins and incapacitating qualities.
Could it mean nothing at all? Certainly.
It could've been entirely unintentional, just a happy little accident.
It could have been very intentional, just some subtle foreshadowing.
Is that gonna stop me from theorizing about the reasons these similarities might have come to be? Of course not!
As far as I know (which, I could very well have just missed something), Kikimora is the only character in the show with red sclera, but she's DEFINITELY the only one to be shown performing this spell on her own.
Was Kikimora specifically chosen as Belos's aide because of her potential capacity to perform such a spell? Like, Belos saw her weird eye, remembered something the Collector told him about the requirements for the draining spell, and went "YOU," before eventually teaching her the spell?
Was her eye modified/replaced to allow her to perform the spell, and thus to better serve her emperor? He's already known to favor unstable, power-hungry people in positions of power beneath him, so she could very well have gotten that job the normal way; then, it would just have been a matter of Belos (and probably whoever was head of the Healing Coven at the time) granting her the eye and teaching her the spell.
Is it just a coincidence that I'm reading WAY too hard into, even within the world of the show?
Who knows!
well. besides the showrunners. im sure one of them knows.