It's popular because they have such contrasting personalities. Sombra is the mysterious hacker while McCree is the cowboy with a rough exterior. The idea of them coming together creates an interesting dynamic.
You can try Archive of Our Own (AO3). It has a large collection of fanfictions including many for the mccree x sombra pairing. The website has a great search function that allows you to filter by tags, ratings, etc.
One great mccree x sombra fanfiction could be 'The Unexpected Alliance'. In this story, they are forced to work together on a mission in a post - apocalyptic world filled with Omnic threats. Their initial distrust gradually turns into respect and then something more.
One great Sombra x McCree fanfiction is 'The Heist and the Heart'. It has an exciting plot where they team up on a mission and slowly discover their feelings for each other. Another is 'Shadows and Sunlight' which delves deep into their different personalities and how they complement each other.
One common theme is the contrast between their personalities. Sombra is mysterious and cunning, while McCree is more of a straightforward cowboy type. Their differences often lead to interesting interactions and relationship dynamics. Another theme is the idea of trust. Since they come from different sides in the game's lore, building trust is a big part of their relationship in many fanfics.
One great mccree x sombra fanfic is 'The Unlikely Alliance' which explores their relationship in the context of a mission. It has well - written action scenes and character interactions.
Another way is to check out fan communities on platforms like Reddit. There are often threads dedicated to Overwatch fanfics, and you can specifically ask for mccree x sombra ones. People are usually very helpful and will recommend some great reads.
There's a fanfic called 'Allied Hearts' that delves into how Sombra and McCree, despite their different backgrounds, find common ground and start to care for each other deeply. It has great characterizations that stay true to their in - game personalities. Also, 'Silent Whispers' is a fanfic that shows their relationship from Sombra's perspective, exploring her inner thoughts as she gets closer to McCree.
In 'king sombra x oc fanfiction', the focus is on the unique pairing. King Sombra has his own backstory and personality in the original source. The OC, on the other hand, is a creation of the fan. When combined, it can lead to some exciting plotlines. It could be a story of love, rivalry, or even a journey of self - discovery for both characters. Writers can use this pairing to explore different genres like adventure, drama, or mystery.
Protection is also a major theme. McCree feels the need to protect Mercy from the dangers of the world they live in, while Mercy protects McCree in her own way, by healing his physical and sometimes emotional wounds.