Destiny Unchain Online (Full Japanese title: Destiny Unchain Online 〜吸血鬼少女となって、やがて『赤の魔王』と呼ばれるようになりました〜, or Destiny Unchain Online: After Becoming a Vampire Girl, I Eventually Became Known as "Crimson Demon King" in English) is an action and fantasy Web Serial Novel written by author resn, which was originally released on the website Shousetsuka ni Narou before being moved to Kakuyomu along with its chronological prequel Worldgate Online in 2021.
The novel follows Mitsuki Kou, a high school student and avid gamer who plays under the handle 'Crim'. During the spring break before joining high school, he's invited to playtest a brand-new VRMMORPG Destiny Unchain Online by his father, who's also the lead developer of the game. After logging into the game with a mysterious 'medical' device named the Cradle, Kou finds himself playing as a... vampire GIRL?! Using his usual 'Crim' handle, Kou will meet new friends and aim for the top!
The Web Novel has a manga adaptation with six volumes released as of this writing, which loosely follows and expands on the original plot, and a light novel which is a more faithful adaptation of the Web Novel, both illustrated by yachimoto.
Tropes
- 20 Minutes into the Future: The city where Kou lives in, briefly depicted in the first chapter, has a futuristic look and everyone seems to use choker-like device in place of smartphone.
- Adaptation Expansion: The manga adaptation very loosely follows the plot of the Web Novel while massively expanding on everything else. Example: The nameless PK guild who get steamrolled in one chapter in the Web Novel now become a legitimate threat that takes 10 chapters for Crim and co. to defeat. Lycoris' arc seems to head toward that direction as well.
- Adapted Out: The scene where Crim sucks on Freya's blood after the fight with the PK guild is absent from the manga for some reason.
- Anachronism Stew: At first glance, DUO is your standard, run-of-the-mill MMO world full of sword and magic. However, Gnomes (a.k.a robotic humans) is one of the six basic races, and players happily use guns as much as any other weapon. Lycoris' introduction arc follows her and Crim's venture into an underground ruins filled with cyborg zombie mermaids and a giant mecha as the area boss.
- Artificial Intelligence: Every NPC in DUO seems to be one, to the point of being indistinguishable from real life people.
- Attack Its Weak Point: In DUO, landing a critical hit on an enemy's vital organs (brain, spine, heart, etc...) can instantly kill them in a single attack, ignoring their remaining HP. Crim loves going for the throat for this reason.
- Berserk Button: Seeing a PK is enough to send Hinagiku into a murderous rage. If you act the slightest bit like a PK in the same room as Hinagiku, expect her sword on your throat immediately.
- Childhood Friends: Kou and the twin siblings, Hijiri and Subaru.
- Combat Medic: Hijiri's character build, to some extent. She's dressed like a typical healer, is capable of healer spells, but quite bad at doing so. On the other hand, she's the most valuable in combat when she's acting like a tank, using Taunt and Air Ride (think Cover Move from Bofuri).
- Cute Little Fangs: Crim and Hinagiku feature these prominently.
- Daddy Had a Good Reason for Abandoning You: Kou's mother has been missing from Kou's life for years. She makes a cameo in the last page of chapter 5 and refers to Kou as her 'daughter'. It's implied that Kou's mother is a vampire and the 'Cradle' device's true purpose is to transform Kou into a vampire himself (or herself?).
- Forced Tutorial: Every player who sets foot in the First Town Windham for the first time will be forced to undergo a long tutorial. Even Crim, who was sent to somewhere else at the start of the game, is no exception.
- G.I.R.L.: Crim is played by the boy Mitsuki Kou. Subverted when Kou's real life body slowly transforms into that of the in-game Crim.
- Imagine Spot: In chapter 29 of the manga, when the prospect of Crim being kidnapped is brought up, Hinagiku and Freya fantasize about it in really different ways.
- Super Mode: Players of certain "unique" races may gain access to one, which is massively powerful in exchange for severe drawback, making it more of a last restort:
- Crim (Noble Red): Can use Blaze Blood to greatly boost all stats and self-regeneration (becoming a Fiery Redhead in the process). However, Crim is turned into Sleep-Mode Size after the effect expires and she runs out of blood.
- Hinagiku (Silver Fox): Can use Azure Flame to imbue herself with sacred and flame attribute, on top of an attack boost against Demonic enemies. Her HP will continuously drop to 0 in this state, combined with her low base HP, making her a glass cannon.
