A primer for people who are new to Eroica!
TelWoman's comprehensive list of stories to win over someone who never read Eroica fan fiction, and didn't know anything about Eroica
Recommended because they illustrate popular themes explored by fic writers.
In canon, Klaus and Dorian never develop a relationship. Some fic writers do let them get together, though.
Five Days in Padesca, by Laura Kaye https://archiveofourown.org/works/663681
Some fics let them get together, but not before considerable angst and difficulty.
Too Good to be True, by Kadorienne, and its two alternative sequels, The Course of True Love, and The Truth Shall Set You Free https://archiveofourown.org/series/3900
Then there’s the idea that maybe they both enjoy the sparring and teasing but they’re both terrified of what an actual relationship might mean.
Deep Waters, by Thia https://archiveofourown.org/works/992444
One of Dorian’s formative experiences in canon was being coerced into having sex at age 13 by a family friend. A number of fic writers have speculated how that traumatic event might have shaped Dorian’s thinking and behaviour.
Seeing is Believing, by Cassie Ingaben https://archiveofourown.org/works/42265
Other writers have taken the idea of traumatic childhood experiences to explain why Klaus seems to be so uptight about sex.
Peripeteia, by Sylvia https://archiveofourown.org/works/41224
In canon, Dorian only worked for Klaus once, and refused the honey trap request made in The Seventh Seal – but there are plenty of fanfics that have Dorian working for NATO as a contractor.
Moonlight Shadow, by Joram https://archiveofourown.org/works/87974
Klaus & Dorian are tough, ruthless men. They have to be in their respective professions.
Breaking and Entering, by Neery https://archiveofourown.org/works/34385
Klaus’s reputation for courage, heroism and dedication to his job is strong in canon, and in fan fiction too.
Anger Not the Old Lion, by Anne-Li https://archiveofourown.org/works/125877
Fandom often writes Klaus as sexually inexperienced or else not even interested. Is he gay? Straight? Asexual? Is he repressed? Not interested? Hiding a raging sexual appetite?
Not the Only Fruit, by Nomad https://archiveofourown.org/works/835183
Some writers play with alternate universes. Here’s a story that re-tells an early episode from the manga, set in an odd universe in which sea-creatures pose an ever-present danger to humans, and humans have interbred with sea-creatures for generations.
A Thousand Kisses … and Sea Monsters, by Anne-Li https://archiveofourown.org/works/4296882