One idea could be Master Chief being thrown into the Mass Effect universe during a crucial moment in the fight against the Reapers. His combat skills and Spartan abilities would surely turn the tide in unexpected ways. For example, his mastery of close - quarters combat could be a game - changer in battles where the Mass Effect characters are more used to ranged combat with biotics and guns. Another plot idea could be about the technology exchange. The Covenant technology that Master Chief is familiar with and the advanced tech in the Mass Effect universe might create some really interesting scenarios. Maybe the UNSC and the Citadel Council could form an alliance based on shared technology interests.
A possible plot could involve Master Chief's AI, Cortana, interacting with the various AIs in the Mass Effect universe. Her unique relationship with Master Chief and her own intelligence could lead to some fascinating developments. For instance, she could help decrypt some of the Prothean technology that has been a mystery for so long. Or, she could team up with EDI to fight against a common threat. Also, Master Chief's indomitable will and his sense of duty could inspire characters in the Mass Effect universe like Shepard. This could lead to a story where they both learn from each other's leadership styles and use it to combat the forces that threaten their respective universes.
One interesting plot idea could be the combination of the technology from Mass Effect and the world - building of Anthem. For example, Shepard could find himself in the world of Anthem and have to adapt to the javelin exosuits while also dealing with the local threats. Maybe the Reapers start to target the world of Anthem as well, and the two groups from different universes have to team up to fight this common enemy.
Well, Master Chief would likely start by assessing the threats in the Mass Effect universe. He'd notice the Reapers right away as a major threat. His military training would kick in, and he'd try to find ways to combat them. In terms of adaptation, he'd probably look for allies. He might be initially skeptical of the alien species but would soon realize that they can be valuable partners. For instance, he could team up with the Turians, who also have a strong military tradition. He'd also have to adapt to the different forms of transportation, like the Mass Effect relays. His first encounter with using one of these relays might be a bit of a shock, but he'd quickly figure out how to use it to his advantage.
One interesting plot combination could be the use of Crysis' nanosuit technology in the Mass Effect universe. For example, Shepard could get ahold of a prototype nanosuit that gives them enhanced combat abilities, like increased speed and strength, which would be a huge advantage against the Reapers. Another could be the merging of the alien races from both universes. Maybe the Turians and the Ceph could form an uneasy alliance due to a common threat.
One of the most interesting storylines could be the interaction between the different species in Mass Effect and those from Stargate. For example, how would the Asari react to the Goa'uld? The Asari are a long - lived, biotic - using species in Mass Effect, while the Goa'uld are parasitic snake - like beings in Stargate. Another cool idea is the technology exchange. The Mass Effect universe has advanced biotic and cybernetic technology, and Stargate has its own unique wormhole - based travel and Ancient technology. A fanfiction could explore how these technologies might be combined or used against each other. Also, the cultural clashes would be fascinating. The different races in Mass Effect have their own moral and ethical codes, and the same goes for the races in Stargate. How would they deal with each other's values?
A really cool plot twist could be that the Protheans, who are an ancient and advanced race in the Mass Effect universe, had actually encountered Cthulhu Mythos entities in the past. This could explain some of the mysteries surrounding their downfall and the disappearance of their technology. Maybe they tried to harness the power of these otherworldly beings and it backfired, leading to their civilization's collapse. This revelation would not only change how we view the Protheans but also add a new element to the overall lore of the Mass Effect universe.
One idea could be having the XCOM soldiers use their combat skills in the Mass Effect universe. Maybe they are sent to help fight against the Reapers. They could introduce their unique tactics and weaponry to the Mass Effect races.
One idea could be the integration of the mobile suit technology from Gundam into the Mass Effect universe. For example, Shepard's team could discover a lost Gundam unit and try to figure out how to use it against the Reapers. Maybe the advanced beam weaponry of the Gundam could be a game - changer in the fight.
A possible plot is that a Mass Effect technology is introduced to the Naruto universe. Maybe a Mass Relay is found in the Hidden Leaf Village. This could lead to a whole new set of adventures as the ninja try to figure out what this strange technology is and how it can be used. Or, characters from both universes could be combined. Like a Turian with Sharingan abilities.
Another plot could involve a shared enemy that exists in both universes. The combined forces of Mass Effect races and Destiny Guardians have to figure out how to defeat this enemy. They would need to overcome their differences in culture and combat styles to be successful.
One interesting plot twist could be the combination of Mass Effect's biotics with Warhammer's psychic powers. Imagine a character who has both and has to learn to control this new, extremely powerful force. It could lead to a situation where they are feared and hunted by both sides of the crossover world.