Note: Images represent only vaguely of their appearence.
Ashaveer (Angel) - Mother of Meiyaku & Braze. Originally possessed by Cheng (the red fire elemental dragon in Vogue's picture below). She is of noble blood from a kingdom since destroyed by Cheng's warriors. Married to Sekkou, demon who banished Cheng to another world, through his mighty sword.
Braze (Demon) - Son of Sekkou & Ashaveer, Twin to Meiyaku. His spirit dragon's name, Evodia. Controller of blood & fire. Great healing capabilities. 
Meiyaku (Greater Demon) - Daughter of Cheng & Ashaveer, Twin to Braze. Child of Nightmares. Powers of void, shadow, rebirth. Kills her victims rather sadistically, loves to torture them by literally holding them between life & death. Weakness is herself. Her body is weak & sick, tainted by the good blood of her half twin brother Braze. Is after Cheng's powers to make her whole.
Vogue (Chimera) - Creation of Meiyaku & Braze. Born from the body of a snake, she holds parts of Cheng's soul, Braze's blood & Ashaveer's flesh.
