One great 'Command and Conquer Mass Effect fanfic' is 'The Convergence'. It combines the strategic elements of Command and Conquer with the rich lore of Mass Effect in an interesting way. The characters are well - developed and the plot keeps you hooked from start to finish.
I've also read a fanfic titled 'Hybrid Wars'. In this one, the authors blend the gameplay mechanics of Command and Conquer into the Mass Effect setting. It's a long read but worth it as it delves deep into how the two universes could be integrated, with detailed descriptions of new units and strategies.
What makes 'Command and Conquer Mass Effect fanfic' stand out is the way it can blend the different aesthetics and gameplay concepts. The sleek, futuristic look of Mass Effect and the more gritty, war - focused style of Command and Conquer can be mashed together. You could have a story where a Shepard - like character uses the resources and strategies from Command and Conquer to take on the galactic threats in Mass Effect. It opens up a whole new world of fan - created narratives that are different from the official storylines of both franchises.
I really liked 'Atlas: Unseen Stories'. This fanfic explores some of the untold stories related to the Atlas in the Mass Effect world. It shows the daily life of the crew, their struggles, and how they contribute to the overall story. It's a bit more character - driven compared to other fanfics, which makes it really interesting as you get to know the lesser - known aspects of the Atlas and its crew.
I highly recommend 'Tali's Redemption'. In this fanfic, Tali faces a personal crisis after a mission gone wrong. It's a great read as it shows her vulnerability and her strength in overcoming it.
One great 'Samara x OC' Mass Effect fanfic is 'The Enigmatic Bond'. It delves deep into the relationship between Samara and an original character. The OC is a biotic with a mysterious past, which draws Samara's attention. Their interactions are well - written, exploring themes of loyalty and the struggle between the Justicar code and personal feelings.
There are some great ones out there. You can start by looking on fanfic platforms like Archive of Our Own. Some fanfics might focus on Jack's relationship with the main character in new and interesting ways, or they could explore Jack's backstory more deeply within the context of the Mass Effect universe.
One great MLP Mass Effect fanfic is 'Equine Shepard'. It combines the colorful world of My Little Pony with the epic space opera of Mass Effect in a really interesting way. The characters are well - developed and the plot has a good mix of action and humor.
One great Mass Effect OC Quarian fanfiction is 'The Quarian's Journey'. It focuses on a unique OC Quarian character who embarks on a mission to find a new home for her people. The story is filled with interesting character development and exploration of Quarian culture.
I've come across a fanfiction where Shepard becomes a vampire and it's set during the events of the Reaper invasion. Titled 'Vampire Shepard Against the Reapers', it's really cool. The author explores how Shepard's vampiric abilities could be both an advantage and a hindrance. For example, they can use their speed to surprise enemies but they also have to constantly find sources of blood, which is scarce during the chaos of the invasion.
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.
I really liked 'When Reapers Met the Ancients'. This fanfiction has a crossover between the Reapers and an ancient civilization in the Mass Effect world. It delves deep into the lore of both and how their meeting could change the course of the entire universe. It's a long read but definitely worth it for those who love exploring the deeper aspects of the Mass Effect universe.