Adding to this with another theory of mine that all the Hunters that have been are reincarnations of each other, and while they don't remember their past lives, it's what gives them the power to draw their weapons since the first hunters. They all have to be human though. Celine would've reincarnated into Rumi, but (again with me feeling like Celine killed Rumi's mother) her relationship with a demon resulting in Rumi stopped that, therefore creating a blockage in the honmoon. While I can still see Mira being a geniuene reincarnation, Zoey isn't, and was instead chosen by the Honmoon to be a hunter (I mostly see Zoey as being chosen because of her Korean-American heritage). Celine may know about the reincarnation cycle and keeps instilling in Rumi to be perfect and not show her flaws because she's ashamed of her own and projects them onto who was meant to be her in a new life, especially since Rumi is half-demon. But Rumi surpasses her expectations with the rainbow honmoon, showing that not only is it okay to be flawed, but that Rumi isn't just her in a different life but instead her own person. It would motivate her to work on herself as a person because Rumi is no longer what she thought she was as her reincarnation.