One interesting character could be Zenon's best friend. You can explore their friendship more deeply, like how they support each other through tough times in the 21st century. Another could be a mysterious scientist she meets. This scientist might be working on a top - secret project that Zenon gets involved in. And there's also the possibility of writing about her school teacher who has a really unique teaching style and challenges Zenon in different ways.
Since lemon fanfics are inappropriate, we should focus on their general characteristics from the official story. Asta is highly determined and energetic, always striving hard despite his lack of magic initially. Yuno, on the other hand, is more calm and has a natural talent for magic. They both have a strong bond as rivals and friends.
Noelle could be a great addition. Her water magic is quite powerful and she has a complex relationship with both Asta and Yuno. She could be a source of both support and conflict in the fanfic. Another good character is Luck. His lightning magic and his rather unpredictable nature can add a lot of action and excitement to the story.
To develop Protozoa, think about how it interacts with its environment. If it's in a lab setting, how does it react to different stimuli? For Zenon, show her growth. At first, she might be a bit hesitant about her relationship with Protozoa, but as the story progresses, she becomes more confident and protective. You can also develop their relationship by having them face challenges together, like when other scientists question Zenon's attachment to Protozoa.
I'm not sure if 'yuno visual novel' is popular. There are so many visual novels out there, and without more information about this specific one, it's hard to say. It might be popular within a niche group of visual novel fans who are interested in the particular themes or style it offers.
One idea could be that Protozoa, being a microscopic organism in nature, has some sort of special connection to Zenon. Maybe Protozoa is a sentient being in this fanfiction and can communicate with Zenon telepathically. Zenon could be on a scientific mission to study Protozoa but ends up learning life - changing lessons from it.
They develop Yuno's character through her actions. Yuno's yandere nature can be shown through her jealousy. If Yuki so much as talks to another character, Yuno might have a strong reaction. Writers also use her internal monologues to let the readers understand her twisted thought process and how her love for Yuki is all - consuming. She might think things like 'Yuki is mine and no one else can have him' which shows her possessive side.
I'm not entirely sure specifically what 'yuno visual novel' is about without more context. It could be a story about a character named Yuno, perhaps in a fictional world with various adventures, relationships, and challenges. Maybe it involves elements like mystery, romance, or action within the framework of a visual novel.
First, make sure your device meets the game's system requirements. After that, launch the game and pay attention to the initial instructions and menus to understand how to progress and interact within the game. Also, check online for any available walkthroughs or tips if you get stuck.