Planned out familial trauma before the campaign started and ended up unimaginably worse by the end of it.
Karmos basically grew up living in his older sister’s Malaia’s shadow, and he was perfectly content with that. Things only became rocky once Malaia started to grow closer to Laurent, the two’s childhood friend and Karmos’s unrequited crush. He never had the heart to confess to him though because of how much Malaia loved him, and so when Malaia and Laurent eventually began dating and got married together, all Karmos could do was support his sister and push his feelings aside. Malaia eventually worked for the government, taking care of the magical items in the city, Laurent became a folks hero, particularly a firefighter, and Karmos began his life as an acolyte to Melora. Then the married couple had a child, Quirkilxa, who Karmos helped care for, and would continue to care for after Malaia and Laurent died overseas going on a vacation which Karmos insisted they take. He became a protection cleric after that, and made it his goal to protect Quirkilxa.
When the campaign starts, and Karmos starts working odd jobs to help make ends meet, and Quirkilxa tags along because she wants to become more like her father! A lot of bullshit happens, but basically Karmos and Emrys Perdue gets in an altercation and dies during an explosion, and then Galwyn decided to revive them in turn for a favor. The whole campaign is mainly about doing missions for him, and then the group learns that they have to prevent an apocalypse who they learn is being brought upon by Aracheus Perdue, the uncle of Emrys and Wyn. During one of the fights, Quirkilxa’s wild magic turned her into a baby and she died, and she was reincarnated into a aged-up orc, who later died in actual combat as a sacrifice. After the whole war, Karmos and Emrys started to date. He's trying to cope with the death of Quirkilxa and help Emrys cope with the death of Wyn. While he doesn't see his future as being bright, he's comforted that he's not alone since Emrys is with him and he's trying his best to learn how to be okay again.
Post campaign, Karmos and Emrys has decided to settle down on a farm raising animals, with A LOT of dogs. Around after 3 years of dating, the two somewhat abruptly got married after Wyn canonically dies in a future campaign in the same world. Since then, they've been married for 5 years and during one of their picnics, they've discovered a fire that was started by an abandoned fire genasi baby who they decided to name Quinn in homage to Quirkilxa and Wyn.