First, think about their semblance. It should be something that fits within the RWBY universe's rules of magic and power. For example, if it's a power related to nature, explain how it interacts with the existing Grimm and Dust in the world. Then, consider their backstory. Maybe they grew up in a small village on the outskirts of Vale that was constantly under threat from Grimm. This would shape their personality as someone who is tough and determined.
To create a believable self - insert in 'Mass Effect AI self - insert fanfiction', the writer should consider the character's skills and knowledge. If they're supposed to interact with AI, they should have some relevant knowledge, like programming or understanding of artificial intelligence concepts. Also, their reactions to the strange new world should be realistic. They might be in awe of the advanced technology at first, and gradually adapt. Their relationships with the existing characters, both organic and AI, need to be developed carefully. They can't just be instantly best friends with everyone. There should be a natural progression of trust and understanding, just like in real - life relationships.
To create a believable self - insert character, start with your own personality traits and exaggerate or modify them for the Marvel world. For example, if you're a very organized person in real life, your character could be a strategic mastermind in the story. Also, give your character a backstory that explains how they got involved with the Marvel universe. It could be something like they were at the wrong place at the wrong time during an experiment gone wrong.
To write a believable character in a Percy Jackson normal human self - insert fanfiction, start with giving them relatable traits. For example, they could be a bit clumsy or shy, like many real people. Also, give them a backstory that makes sense for a normal human. Maybe they are a big fan of Greek mythology before getting thrust into the Percy Jackson world. This will help the readers connect with the character. Their reactions to the strange and magical things in the demigod world should be realistic too. They should be scared or amazed in appropriate situations.
First, consider the background. If you're from Westeros, which region are you from? The North would mean a tougher, more no - nonsense attitude, while someone from the Reach might be more refined. Also, think about your skills. Are you a good fighter? A healer? Or a diplomat? These skills will shape your interactions in the story.
To make the character believable, they need to have goals and motivations. In a Rosario Vampire self - insert fanfiction, their goal could be as simple as wanting to graduate from Yokai Academy safely. But along the way, they might develop other goals like helping a certain character overcome a problem or trying to understand the true nature of the different yokai species. Their reactions to the various situations in the story, like when facing a vampire's bloodlust or a werewolf's temper, should also be in line with their character traits.
First, give them a backstory that ties into the RWBY universe. For example, they could be from a family that has a history with Grimm research. Second, give them flaws. Don't make them all - powerful. Maybe they are afraid of the dark because of a bad encounter with Grimm at night. Third, have them develop relationships with the existing characters. If they are constantly butting heads with Yang because they are too reckless, it makes them more believable.