Reikina and Hirei Headcanon
Inspired by this headcanon
Hiei is downright pissed that Rei is banging dating his sister but can’t say anything about it due to not wanting Yukina to know he’s her brother and so settles for annoying Rei even more whenever she’s around Yukina.
Meanwhile Rei and Yukina are the happiest love birds ever, being deeply in love with Rei doing everything in her power to keep her gf safe and Yukina helping her gf out at the shrine. Then one day someone tells Rei that Yukina hasn’t mentioned looking for her brother in a while and Rei is confused because her precious ice nugget didn’t mention anything about having a brother and so asks her and Yukina tells her the whole story. Rei then asks her why she hasn’t told her about finding her brother because she could’ve helped too and then Yukina says it’s because she’s already found him and tells her it’s Hiei. After remaining silent for a couple of minutes (while screaming rage and profanities internally) Rei asks Yukina why she hasn’t told anyone about this, Hiei especially, and her sweet frosty gf slowly tears up then breaks into full on hiruseki stones saying that Hiei knew the whole time and never bothered to tell her and she feels inadequate and unworthy to even be his sister. Rei takes her gf into her arms holding her close and never letting go, assuring her she’s a wonderful girl and any idiot would be lucky to have her for a sister. Yukina sniffles and thanks her gf and cuddles into her, unaware of the fiery rage and vengeance burning in Rei’s eyes.
Sometime later Hiei makes one of his visits to the human world to check up on the others (Yukina especially) and heads to Genkai’s temple. Once there he senses Rei hiding in the shadows and tells her to come out, mocking her of course. Rei does come out, all transformed into her sailor fuku, and then the ultimate battle between demon and sailor senshi occurs with wards, swords, and flames of course and ends with the clash of Mars Snake Fire and Dragon of The Darkness Flame, leaving to two to just plain beat the shit out of each other. Rei gets the upper hand and punches Hiei down to the ground and keeps punching him saying: “This is for me! This is for Yukina! This is for making Yukina feel unworthy! This is for making Yukina feel inadequate! And this is for not telling Yukina YOU’RE HER BROTHER!” With that one last punch, Sailor Mars just flops down on her back next to Hiei, panting for breath while Hiei is just downright fucking shocked and asks her how she knew. She tells him everything and tells him he better explain to her why he never told Yukina before she Burning Mandala his ass into Makai or Reikai (she hasn’t decided on which yet) and Hiei tells her and once done Rei uses what little energy she has left to slap him and calls him an idiot and says that Yukina cares about him and that he better tell her soon before she exorcises his ass into oblivion. Yukina and Genkai then come to them asking what had happened, with Genkai being pissed that they destroyed some of her property, and when they get up Hiei goes to Yukina saying he has something important to tell her. Cut to about a thousand years later in Crystal Tokyo, where Hiei and Sailor Mars have one of their classic arguments at Thanksgiving or whatever while the Reikai Tantei and Sailor Senshi watch on in amusement, annoyance, and while betting who’s gonna break out the flames first while Yukina watches her wife and brother in delight while holding one of her and Rei’s children.
