Liara is frequently featured in 'mass effect crossover fanfic'. Her knowledge of Prothean technology and her overall intelligence can be used in various crossovers. For example, in a cross - over with a more magical - based science - fiction universe, her understanding of ancient technology could be a bridge between the two worlds. Another popular character is Tali. Her skills as an engineer and her relationship with Shepard make her a natural choice for fanfic authors to include in crossovers.
Thane is often seen in 'mass effect crossover fanfic' as well. His assassin skills and his complex backstory can add a lot of depth to a crossover story. In a crossover with a darker, more noir - like universe, Thane could be a great fit. And of course, Wrex. His brute strength and his leadership among the Krogan can be interestingly explored in crossovers, especially when paired with characters who have different leadership styles.
Garrus Vakarian might also be a common character. His relationship with Tali in the original games means that in a crossover, their dynamic can be explored further. He could be involved in protecting Tali or working with her in a new situation that the crossover creates.
Aria T'Loak is a character that often shows up. She is a powerful and shrewd leader in the 'Mass Effect' universe, and her leadership style and influence can be a great addition to empire - building stories. And then there's Javik, the last Prothean. His knowledge of ancient civilizations and advanced technology can bring a unique perspective to the empire - building process.
Definitely Commander Shepard from Mass Effect. He/She is the central character in Mass Effect and would be a natural fit to interact with XCOM forces. Also, XCOM's Central Officer or top - ranking soldiers could be prominent. They could be the ones making decisions on how to deal with Mass Effect threats or form alliances.
Master Chief from Halo is an obvious choice. His super - soldier skills and stoic nature would be really interesting to see in the Mass Effect universe. Another one could be Commander Shepard from Mass Effect. Putting Shepard in the middle of a Halo - style conflict would be exciting. And Cortana, the AI from Halo, could also play a major role. Her intelligence and relationship with Master Chief could be explored in new ways when combined with the Mass Effect elements.
Shepard from Mass Effect is a very likely character. Given their leadership skills and experience in dealing with various alien threats, they would be a natural fit in a crossover. They could potentially lead XCOM forces or at least be a key figure in coordinating between the two universes.
Shepard is often a central character in Mass Effect harem fanfiction. Given their role as a hero in the main games, it's easy to imagine them in a harem situation. Liara is also very popular. Her connection with Shepard in the original story and her asari abilities make her an interesting addition to any harem. Garrus is another one. His loyalty and unique turian characteristics can add a lot to the harem dynamic.
Kakashi could be another one. His past traumas and his skills as a ninja make him a great candidate to be involved in a darker storyline. He might be able to use his experience to navigate the challenges of the crossover world.
Yugi Moto is often featured. He's a very popular character in the Yu - Gi - Oh! world, and in the crossover fanfiction, he might be the one to encounter the Infernity cards or be involved in duels related to them. Another one could be Kaiba. His competitive nature and love for powerful cards could lead to him being interested in the Infernity archetype.
Shepard is a very common character to be at the center of a human harem in fanfiction. Given their heroic status and the fact that they interact with so many different species, it's easy to imagine a harem forming around them.
Ash Ketchum is often a central character. His experience and knowledge from different Pokemon regions can be a great asset in a crossover setting. Then there's Pikachu, of course. It's so iconic that it's almost a must - have in any Pokemon - related fanfic. Another popular character could be Misty, especially when exploring water - type Pokemon - related crossovers.