I've read a few Steve and Kono pregnant fanfictions. In one, the pregnancy was a surprise and it led to a whole new adventure for them. It showed how their relationship deepened as they prepared for parenthood. Another one was more about the challenges they faced, like Kono's health issues during the pregnancy and how Steve supported her through it all.
One emotional moment could be when Kono is injured during a mission and her friends fear for her life. They gather around her in the hospital, and the worry on their faces shows how much she means to them.
She could also develop more patience. Dealing with the physical and emotional changes of pregnancy might make her more patient with difficult suspects or witnesses. Instead of getting frustrated quickly, she might take a more gentle approach, which could lead to better results in investigations.
Some writers develop Kono's character by making her reflective when she's hurt. She might think about her past actions, decisions she made that led to the situation she's in now. Maybe she regrets some things or realizes she needs to change certain aspects of how she approaches her work or relationships. This self - analysis is an important part of character development in the context of her being hurt in fanfictions.
The world - building in the 'Kono Suba Light Novel' is also appealing. It has a fantasy setting with various magical elements and creatures. The way the author describes the different quests and adventures that Kazuma and his party go on, from fighting simple slimes to dealing with more complex magical threats, makes for an exciting read.
Darkness is also a main character. She is a crusader. She has some rather unusual interests and is constantly getting into strange situations. Her dynamic with Kazuma and Aqua adds a lot of humor to the story.
I'm not sure specifically as it could be a relatively unknown or niche visual novel. It might be about a unique story set in a particular world, perhaps with themes related to the end of this world ('kono yo no hate' can mean 'the end of this world' in Japanese), but without more information, it's hard to say for sure.
Some fandom - specific forums might also have Adam and Kono fanfiction shared by fans. These can be a bit more niche but might have some unique stories that you won't find on the bigger platforms.
There could be a fanfiction where Adam and Kono go on a road trip. Along the way, they have deep conversations and strengthen their relationship while also getting into some interesting situations like helping a small town with a mystery.