A great one often has a well - developed Geth OC. This means the character has a unique personality, backstory, and goals within the context of the Mass Effect universe. For example, it could be a Geth that has different views from the rest of its kind.
Well - developed characters are key. For a Geth OC, it should have unique characteristics that set it apart from the regular Geth we see in the game. Maybe it has a different view on organics, or a special ability. A good plot is also essential. It could be about the Geth OC's journey of self - discovery, or its interactions with other characters from the Mass Effect universe, like Shepard or Tali.
First, do your research on the Geth. Know their lore, how they function, and their place in the Mass Effect universe. For the OC, create a well - rounded character with a clear backstory and motivation. Make sure the OC's personality and goals interact in an interesting way with the Geth's nature.
One great Mass Effect OC Geth fanfiction is 'The Geth's New Ally'. It tells the story of an original character who forms an unexpected bond with the Geth. The OC's unique perspective and the exploration of Geth culture make it a really interesting read.
One possible fanfic could focus on the cultural exchange between humans and the Geth within the alliance. Maybe a human engineer is paired with a Geth unit to work on a new technology. They start off distrustful of each other, but as they work together, they come to understand each other's capabilities and values.
Some Mass Effect - related forums or communities also share fanfics. For example, the official Mass Effect subreddit might have threads where fans recommend their favorite Geth OC fanfics. You can engage with the community there and ask for suggestions as well.
One interesting fanfiction could be 'The Geth and the Outsider OC' which explores the relationship between a unique OC and the Geth in a post - Reaper War scenario. Another might be 'OC's Alliance with Geth X' which focuses on how an OC forms an alliance with Geth X against common enemies. There's also 'Geth X and the Mysterious OC' which delves into the mystery surrounding an OC's connection to Geth X.
There could be a story about a human scientist who discovers a way to enhance the Geth's programming in a way that gives them more emotions. This causes a stir within the Geth collective as they debate whether this is a positive change or a threat to their identity. Meanwhile, some humans fear that the more emotional Geth might become unpredictable.
Some fanfictions might center around a Geth's relationship with a particular character. Maybe a Geth forms an unlikely alliance with a Krogan. The story could detail how they overcome their differences and work together towards a common goal, while also exploring the unique nature of the Geth's thinking process.
You can try websites like FanFiction.net or Archive of Our Own (AO3). They have a vast collection of Mass Effect fanfictions. Just use their search functions and type in relevant keywords like 'OC', 'Geth X' and 'Mass Effect' to find what you're looking for.