The story of this boy, who has become one with a demonic weapon and is drawn into a cruel fate in which he must face countless battles, can be seen as either the story of "a beautiful weapon and an ugly person" or of "the cruelty of weapons and the beauty of humans." This is a completely new world of comic noir.
An anime adaptation by LandQ Studios premiered on Netflix on March 23 2018 labelled as Part 1. Part 2 was released on July 30, 2018.
Sword Gai provides examples of:
- Alien Blood: Busoma seems to have dark purple blood.
- All Myths Are True: The weapons come from all sorts of regions and mythologies.
- And Then John Was a Zombie: At the end of part 1 of the anime Seiya becomes a Busoma to save Gai.
- Anyone Can Die: While part 1 had very few important deaths, part 2 ramps it up with the deaths of Seiya, Mina, Marcus, Kyouka, Takuma, Himiko, Kazumo, and Shin at the very end.
- Artificial Limbs: Gai lost his right arm to Shiryu, and Amon turned the cursed blade into an artificial arm.
- Axe-Crazy: Most Busoma can only think of something: to slaughter everything.
- Bare-Fisted Monk: The Gabi sect doesn't use weapons and only fights with their bodies so they aren't corrupted like the Chrysalids.
- Big Brother Mentor: Naoki serves as this for Marcus while Seiya takes this role for Gai.
- Bitch in Sheep's Clothing: Midoriko plays the role of a fun-loving idol in public, but in private she's rather nihilistic and mean-spirited.
- After becoming possessed by Flamberge she turns into a full-fledged Evil Diva.
- Bittersweet Ending: The anime ends this way. Grimms is defeated and humanity is safe, but it came at the cost of the lives of Kyouka, Shin, and basically every other Chrysalid in Shoshidai. Busoma are still out there, including Armys, but Kuromaru has finally found a true friend in Rie Matoba, and Gai and Sayaka finally return to their peaceful lives.
- Bloodbath Villain Origin: Every cursed weapon has an origin story full of blood.
- Blood Knight: By nature the cursed weapons are only driven by one thing only: to kill.
- Casting Gag: This isn't the first time Yūto Uemura requires a mentor to control his powers.
- Cool Old Guy: Kigetsu is undoubtedly one, and he even freaks out Seiya.
- The Corruption: Every weapon can eventually turn its wielder into a Busoma, is only a matter of time.
- Cute and Psycho: Midoriko was this even before becoming possessed by Flamberge, she's only much more open about it after being possessed.
- Dark and Troubled Past: Gai and Marcus have rather sad backstories.
- Dark Is Evil: Zsoltgewinn has control over darkness, and is by far the most evil of the cursed weapons.
- Deal with the Devil: Azoth's backstory centers around this between the alchemist Paracelsus and one of these. Accepting the possession of a cursed weapon can also be seen as this.
- Disappeared Dad: Kyouka is actually the daughter of Takuma Miura, the wielder of Zsoltgewinn
- Draconic Humanoid: The creator of Shiryu was apparently one of these.
- Evil Sounds Deep: Fittingly, Grimms has a deep and sinister voice.
- Evil Weapon: The entire premise centers around cursed weapons.
- Foreshadowing: When Naoki jokingly asks Marcus if he would fall in love with Mina too, Marcus answers she's not his type. So after Naoki is terminated, the Shoshidai give Mina a new face they know will appeal to Marcus.
- Gonk: Yasuko is very fat and certainly not attractive to look at.
- Hidden Villain: Grimms didn't show himself to the heroes until the final episode of part 1.
- Identity Amnesia: The more a person remains bonded to a cursed weapon, they lose more of themselves to the weapon.
- Know When to Fold Them: Flamberge always seems to know when to leave.
- Last Episode, New Character: Himiko, the head of the Gabi only appears in the last episode of part 1 of the anime.
- Mentor Occupational Hazard: Naoki serves as mentor for Marcus, and he's terminated once his corruption becomes too much.
- Mugging the Monster: A pair of thugs thought it was a good idea to try and pick up Midoriko. Considering those guys had beaten up Shin earlier for no reason, you don't feel too sorry for them.
- Not Distracted by the Sexy: Kyouka has no problem looking at a completely naked Seiya without blinking.
- Older Than They Look: Seiya may look in his twenties, but thanks to the Cold Sleep he's actually much older.
- Our Fairies Are Different: The backstories of Nebestigma and Halbert involve faeries of different types.
- Parental Substitute: Amon raised Gai ever since the boy lost his parents.
- Playing with Fire: Flamberge gives its wielder the power over fire.
- Rings of Death: Seiya‘s weapon is a chakram made of golden energy.
- Sealed Evil in a Can: The alchemist Paracelsus sealed a demon within Azoth's sword.
- Shock and Awe: Naoki's cursed weapon Fallagon has power over lightning.
- Sinister Scythe: Grimms fittingly wields a massive and intimidating scythe.
- Skewed Priorities: Soun of the Gabi sect decides it's more important to fight Seiya for being a Chrysalid than continue his search for a Busoma. The Busoma in question takes advantage of the opening and kills him from his own shadow.
- Strong Family Resemblance: Kyoka wears glasses and has slightly grey hair, just like her father Takuma.
- Unperson: After Naoki is terminated, Mina is recreated as Marcus' counselor Aya, heavily implying this isn't the first time she has changed face.
- Wealthy Philanthropist: Shin has no problem financing whatever charity work catches his fancy.
- Your Days Are Numbered: Chrysalids are eventually corrupted by their weapons, becoming a Busoma, hence why they enter into Cold Sleep to slow down the process.
