For a Sesshomaru and OC fanfiction to be the best, the relationship development between them is key. It should be a gradual and believable process. Maybe they start as enemies, and through a series of events, they come to understand and respect each other. The plot also needs to be engaging. It could involve a quest that they embark on together, or a mystery that they solve. Good writing, with vivid descriptions of the Inuyasha universe and its characters, also adds to the quality.
One great place to find Sesshomaru and OC fanfiction is Archive of Our Own (AO3). It has a large collection of fanfics, and you can filter by tags related to Sesshomaru and original characters. Another option is FanFiction.net. Just search for 'Sesshomaru and OC' in the search bar, and you'll get a list of relevant stories. Some Tumblr blogs also share and recommend such fanfictions.
One great 'Inuyasha Sesshomaru x OC Fanfiction' is 'A Bond Beyond Time'. It has a really interesting plot where the OC is a time - traveler who gets entangled with Sesshomaru's quest. The way the author develops their relationship is quite engaging.
You can start by looking on fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. AO3 often has a great variety of Inuyasha Sesshomaru OC fanfictions with different themes and writing styles. FanFiction.net also has a large collection, though the quality may vary more. Another option is to join Inuyasha - related forums or groups on social media platforms, where fans might share their favorite OC fanfictions or even write their own and post links there.
One great sesshomaru and rin fanfiction is 'The Bond Beyond Time'. It beautifully explores their relationship as Rin grows up under Sesshomaru's protection. It shows how their bond deepens over the years and the challenges they face together.
One great 'kagome and sesshomaru fanfiction' is 'The Unlikely Bond'. It explores their relationship in a very unique way, with Kagome gradually breaking down Sesshomaru's cold exterior.
One common theme is the struggle of an ordinary oc becoming worthy of a powerful being like Sesshomaru. It often involves the oc having to prove themselves, either through strength or some other special quality.
A common element is the exploration of Sesshomaru's character in a new light. Since he is often seen as a stoic character in the original, in yaoi fanfiction with an OC, his softer and more emotional sides might be revealed. For example, his vulnerability in the face of his feelings for the OC.
I really liked 'The Moonlit Mate'. In this fanfiction, the OC is a powerful healer who catches Sesshomaru's attention. The story is filled with adventure as they face various challenges together. It also delves deep into Sesshomaru's character, showing how he gradually opens up to the OC. And there's 'Destined Encounter' where the OC has a mysterious past which ties in with Sesshomaru's own journey. The writing is engaging and the relationship between the two characters feels very natural.
The world - building around them. If the fanfiction expands on the Inuyasha universe, adding new locations or lore related to Sesshomaru's world, it enhances the overall experience. For example, if the OC comes from a hidden village with its own set of rules and magic, and this village becomes part of the story's plot as Sesshomaru and the OC's relationship evolves, it makes the story more complex and interesting.