Title: Advice
Author: Dark Ice Dragon
Summary: Before Takio and Tao begin their new job, they go ask for advice first.
Rated: Fiction K

Title: All You Have to Do is Breathe
Author: Dark Ice Dragon
Summary: ·Steampunk AU· There’s a new guy in town, an inventor, and if Tao can steal a few interesting things from him, he’ll be able to eat for a few days, maybe longer. He might even get enough to able to get out of the town! Tao’s wish comes true, just not in the way he expected.
Rated: Fiction T

Title: Awaken
Author: Fleeting Vapor
Summary: When he sleeps, they awaken. Appearances by M-21, Yuna, Frankenstein, Shinwoo, Rai, Regis, Tao, Takeo, Seira, Ikhan, Suyi, and Pedro. Ongoing. Noblesse. Recommended.
Rated: Fiction K

Title; Continuing On
Author: DarkIceDragon
Summary: M-21 knows how this works. He’s been in the Union all these years; he knows what it’s like to be under the roof of scientists. So why aren’t Frankenstein and his master playing by the same rules?

Title: Exceptional Normality
Author: Inu Eve
Summary: Rating may change. M-21 exists, but he can’t be the Ajussi-that’s M-24’s job. A story based on a ‘what if.’
Rated: Fiction T

Title: Fine
Authors: Dark Ice Dragon
Summary: M-21’s phone vibrated, and he frowned for a second before he checked it.
Rated: Fiction K

Title: Forms of Elegance
Author: Shay McSudonim
Summary: Does anyone else think that the Nobles are very much like Tolkien’s elves from “Lord of the Rings”?
Rated: Fiction T
Opinion: It’s more a gaming AU based on LotR than a crossover as the author attempts to explain in the author’s note, but it’s good.

Title: Lost Item
Author: Dark Ice Dragon
Summary: M-21 can’t find his phone.
Rated: Fiction T

Title: Of Nobles and Hilarity
Author: Countess Millarca
Summary: A drabble series describing funny events from when the Old Lord was still alive and causing mischief.
Rated: Fiction T

Title: Play
Author: oOTinaOo
Summary: The school has an open day and the students Rai’s class should do a play… This story is going to be updated, slowly but surely! Look forward to Regis trying to sew, Frankenstein scaring the hell out of two old ladies, a falling prince, witch-rescuing…
Rated: Fiction K+

Title: That’s It?
Author: Dark Ice Dragon
Summary: The signs said M-21 had difficulty sleeping and Frankenstein could hazard a few guesses of the cause. The problem was Frankenstein was sure M-21 would treat any remedy he offered him with suspicion. If he were to keep him busy, however, that could help stop M-21 from dwelling too much.
Rated: Fiction K

Title: The Arrogant Nobles also on AO3
Author: Shay McSudonim
Summary: I like Noblesse, and I like The Arrogant Worms. This is what came of combining them.
Rated: Fiction T

Title: The Principal’s Office 
Author: segfault
Summary: Frankenstein tries to adjust two former assassins to high school life. As if he didn’t already have enough to deal with.

Title: The Legend of Wolf Mountain 
Author: Fleeting Vapor
Summary: M-21 wrapped the bandage around his arm to hide the wound from the children. It felt strange. The teeth marks hadn’t healed yet, and what if Tao’s playful joke was right? What would happen if a werewolf was bitten by a werewolf? Would he transform? The moon was full tonight. The light from it captivated his sight. Noblesse. Recommended.
Rated: Fiction K

Title: This Isn’t Lukedonia
Author: Fleeting Vapor
Summary: Tao, Takeo, and M-21 get off the plane, but this wasn’t their planned destination. Noblesse. Complete. Somewhat crack.
Rated: Fiction K

Title: Trail
Author: Dark Ice Dragon
Summary: He had been alone for a long time, but then he found a trail that brought him to a human settlement.
Rated: Fiction K+

I believe Dark Ice Dragon also on AO3 has many more oneshots that I have not listed here, that are worth checking out. They are the most prolific author of stories for Noblesse that I have come across.