Zero: Black Blood

After explaining the Makai Knights' conduct with human lives when it appears he is planning to kill Iyu, Rei proceeds to fight Ring, who reveals that he left his feather behind on purpose so they can settle this in a battle of both blades and ideals. Even after Ring attempts to have the humans kill him, Rei refuses to stray from his ideals. Yuna and Kain arrive soon after, dealing with the Horrors before they find Iyu. Ultimately, Yuna lacks the will to kill her mother as Iyu uses sings to soothe her. This pacifies the angry mob as Ring finds Iyu singing for her daughter instead of for himself. This causes Ring to assume his true Horror form as ends up falling back into his instincts and devours Iyu after she refuses to sing for him. Once they get the other humans to safety, Rei dons the Zero armor to fight Ring on the back of his Madō Horse Ginga. Once Ring is crippled, Yuna makes her move to make the Horror bleed before being ordered by Zero to sing so they can pacify a healed Ring long enough to destroy him. With Ring no more, Rei tells Yuna that Iyu intentionally allowed Ring to kill her to atone for her actions. Soon after, as Yuna and Kain leave the city, Rei resumes his nightly patrol.

In the community's new location, Satoshi worries about Natsumi until he is calmed down by Iyu after Ring has convinced her that Yuna is safe. After waking the next day, and finding Silva on her neck, Yuna learns that they have been saved by her singing voice. This causes Yuna to remember her time with her parents ten years prior until she caused her mother's blindness and apparent death. When Rei demands to know the meaning for the turn of events, Kain explains that Yuna was assumed dead, as he was partnered to Kuroudo two years ago and witnessed the Makai Knight's death when they saw Iyu. When they arrive at Club Lupo, Natsumi drinks Lupo's Magic Tea so Rei, Yuna, and Kain can track her, but Kain is shocked to hear about Rei's intent to use Iyu to get to Ring. Yuna hears the whole thing as Silva reveals the song she knows to be Iyu's lullaby. The three track Natsumi down to a temple where Nakaima intends to avoid being chosen in the lottery by making her a Blood Dolce. Though Nakaima attempts to cover his actions by claiming to be a stalker before escaping, Kain places a trace on his car. However, they find Nakaima's car damaged after Ring took him to be punished as a mandatory Blood Dolce.

Eating at Club Lupo, Kain reveals that Ring's planned coexistence requires only a few humans sacrificed. Once getting the information, Rei walks off with Yuna adamant to convince the Makai Knight to work with them. After stopping him and Kain from fighting, Yuna explains that she uses the Makai Blade of her father, a Makai Knight who died fighting Ring two years ago, with Kain having grafted the Makai Knight's bone into her arm so she can use her father's sword. Meanwhile, after accidentally hitting a woman with his car, killing her, a young man named Satoshi Wanda calls his girlfriend Natsumi of what happened and frets of learning of the woman's death. As night falls, Satoshi is visited by Ring who offers him a place in his utopia. When Natsumi almost ends up becoming the host of a Horror once she finds Satoshi, Rei arrives with Yuna and Kain as the three fight the Horror before Rei dons his Zero armor to kill it. Seeing Natsumi alive yet unconscious, Rei and his group realize they must infiltrate Ring's community.