ZERO: Dragon Blood is the companion to the GARO spin-off ZERO: Black Blood.
The story follows the Silver Fanged Knight Rei Suzumura, an armored protector (and rival to the titular GARO) whose job revolves around exterminating body-possessing man-eating monsters known as Horrors. Rei travels take him to Runecity, whereupon he saves the life of photographer Alice Hiromi, who is searching for a mysterious egg. Choosing to cling to Rei, she finds herself falling not just into love with the somewhat-aloof Silver Knight, but into the mystical rabbit hole of Makai Culture. At the bottom of that hole waits someone whose rage and despair could release dragonic hellfire upon the world....
Tropes in this mini-series include:
- Adaptive Armor: The Zero Lost Soul Beast can take on the physical traits of an enemy it consumes the blood of. Nipping at Loop turns it further into the Lost Soul Dragon, which utterly overwhelms Makai Dragon Loop using its own powers.
- Affably Evil: Alice, once her trauma and goals are laid bare. Even at her darkest, she's nothing but polite and courteous to Rei.
- Anti-Villain: Alice wants to follow through on the vision she had in her youth and Restart the World, with the hope that the beautiful New Eden that follows is better than what's here now.
- Back from the Dead: Near the end of the final battle, Edel is revived through rather-unknown means and is effortlessly dispatched, having never come to terms with his latent humanity.
- Becoming the Mask: Invoked in #3. After Rei dispatches the Horror that was once a father's son, he's asked by the father to pretend to be the man's son once more. He willingly accepts.
- Big Bad: None other than Alice.
- Big Bad Wannabe: Edel.
- Bittersweet Ending: The Makai Dragon Loop is defeated, Rei is liberated from Lost Soul Dragon's influence, humanity is saved and Rei and Alice even get a very tender moment together. However, Alice dies from the strain of controlling Loop, (who also dies from his wounds) making her the second woman Rei has lost in his life. The only memento of their union is an egg-shaped pendant, which will hatch into a Makai Dragon upon Rei's death.
- Book Ends: The show begins with Zero and Silva on a Horror-hunt. The show ends with them headed to their next one.
- Curb-Stomp Battle: Edel delivers one to the guardians of the Makai Compound he steals the Dragon Egg from.
- Ends up on the receiving end near the end of the show after being revived by (presumably) Alice and attacking Rei out of desperation. He lasts less than a minute before he's cut down.
- Cutting the Knot: Team Rei is quite vocal about how dangerous Makai Dragons can be. When Alice steals the Dragon Egg and lets it hatch, their first instinct is to destroy the baby dragon before it can grow.
- Diedin Your Arms Tonight: After their final battle, Alice bids Rei farewell in a cradled embrace.
- Empathic Weapon: Makai Dragons possess the ability to read the emotions of others. Once Loop is corrupted, its gentleness toward everyone (other than Alice) is replaced with the usual evil dragon-fare; reflective of its new goals.
- Energy Absorption: Makai Dragons feed on Inga to survive. Becomes a Plot Point when Loop becomes ill without Alice knowing the cause, forcing her to find Edel for help.
- Even Evil Has Loved Ones: Subverted. Edel becomes immensely protective toward the Dragon Egg once he discovers Alice has it; wanting to keep the resulting child away from the Humans he hates so much. But, he also wants to turn said child into a Dragon Of Mass Destruction and purge humanity.
- Fighting from the Inside: Implied with Kruegel, the Horror of #3. Horror-possession typically results in a complete Loss of Identity and results in The Heartless, yet small actions from the creature imply some of Jun's love for his father survived the change. The Horror dies in Human form, looking at the pen Jun was going to use to write to his father with an expression of blank curiosity.
- Finger Firearms: The Horror of #3 is able to fire high-speed bullets from its palms in human form. Said bullets also implode their targets.
- Final Solution: His answer to the Makai Order killing his dragon-mother is the extinction of Humanity.
- Humans Are the Real Monsters: In ancient times, the Makai Order captured and killed Edel's mother Nova to learn how to use dragonic power. Edel blames not just the Order, but all of humanity, for her death.
- I Just Want to Be Badass: Kagome's physical frailty prevented her from developing very much magical talent, causing her (and her brother) to seek methods of gaining power. Cue them unsealing the Dragon Knight.
- Killed Off for Real: The Priestess Kagome is gutted by Edel during the four-way battle at the Pier. She doesn't make it.
- Last Request: Played With. The Horror of #3 is willing to let himself be cut down as long as he's allowed to see his father one last time. The Horror attacks Rei when the Knight lets his guard down to consider and a fight ensues. As the Horror dies however, (In Human form, rather than as a monster) it stares at its host's pen longingly, implying the request itself was on some level genuine.
- MacGuffin: The Dragon Egg.
- Mistaken Identity: #3 sees Rei mistaken for another man's son; seemingly on-the-run from a gang until he gets possessed by a Horror. After dispatching the creature, Rei is requested to play the role beiefly by the father one last time. He accepts.
- Morality Pet: Loop, in a literal sense, to Alice.
- The Dragon Nova was Edel's partner, confidant and surrogate mother from childhood. When the ancient Makai Order killed her For Science!, Edel's morals went with her; reducing him to misanthropy incarnate.
- Alice tries to be this to Edel, but fails. Assuming it wasn't part of the act...
- Moral Myopia: Edel hates humanity for killing his surrogate mother to use her power as a weapon. He doesn't see the issue in using the newborn dragon Loop as a weapon. And neither does Alice.
- Mythology Gag: The sheer volume of tributes to Alice in Wonderland could fill an entire football stadium.
- Patrick Stewart Speech: Averted. Edel's frequent delving into Humans Are the Real Monsters gets no response out of the protectors of human life.
- Sealed Evil in a Can: Edel is contained in a glass sarcophagus until Okina and Kagome's ambitions convince them unsealing it will grant them power.
- Suicide Attack: Kagome defiantly stabs her Madou Brush into Edel's chest-armor and turns herself into an Action Bomb. It doesn't end up taking.
- Superpowered Evil Side: Zero Lost Soul Beast (And its upgrade Lost Soul Dragon) is immensely powerful and is right on-par with the Makai Dragon Loop. It's also a monstrous berserker that's rapidly sapping away at the humanity of the one wearing it. If not for Alice and Rekka hitting his armor's Reset Button, Rei would've died.
- Super Prototype: The Dragon Knight is the predecessor to what Makai Knights would be. It practically steamrolls through the main cast until Kagome's Heroic Sacrifice weakens Edel suitably.
- The Dreaded: Edel is this to Kagome. Though instead of causing her to avoid him, she actively seeks him out to destroy him for killing her brother.
- Unusually Uninteresting Sight: Other than Alice, nobody on Rei's side gives much notice to Edel's backstory of tragedy and loss; never really treating him as more than a neighborhood nuisance. Not even the implications of the Makai Order's hand in the death of his mother gets anything beyond one single throwaway line from Rei.
- What Happened to the Mouse?: An exchange between Rei and Alice results in him nearly revealing the death of his original lover and his real name Ginga. The show never follows up on this again.
- Tragic Monster: The Horror Kruegel, whose host's love for his father was strong enough to imprint on it despite its instincts.
