A great plot could be centered around a diplomatic mission during the war. Maybe a small group of humans and Turians who are trying to find a way to end the war before it gets out of control. They have to overcome their cultural differences and the distrust between their species. There could be a lot of internal conflicts within the group as well as external threats from those who don't want the war to end.
Another plot could revolve around the diplomatic efforts during the war. Maybe there's a human diplomat who tries to establish communication with the Turians in the middle of the conflict. They face many challenges, like cultural misunderstandings and the resistance from both sides who are more interested in fighting. The diplomat could befriend a Turian counterpart who also sees the futility of the war and together they try to find a way to end it.
A plot could revolve around a diplomatic mission during the First Contact War. Maybe a group tries to broker peace but faces many obstacles from both sides' extremists. This could explore the complex politics and cultural misunderstandings that fuel the war.
One idea could be a story focused on a small, rag - tag group of survivors who have to band together to take on a Reaper - controlled outpost. They might not be soldiers, but ordinary people forced into extraordinary circumstances.
A possible plot could involve a world war that starts due to a false - flag operation. One faction in the Mass Effect universe frames another for an attack on a neutral planet. This leads to a chain reaction of alliances forming and battles erupting across the galaxy. The Krogan, known for their strength and warrior culture, could be caught in the middle, deciding which side to support based on their own interests.
In Mass Effect fanfiction about the First Contact War, it often explores the initial violent encounter between humans and the Turians. One aspect could be the cultural misunderstandings that led to the war. For example, the Turians' strict military discipline clashed with humanity's more diverse and sometimes chaotic approach to warfare.
One idea could be to focus on a group of human soldiers who are stranded behind Batarian lines during the war. They have to rely on their wits and each other to survive and find a way back to their own forces. Maybe they form an unexpected alliance with a group of Batarians who also oppose the war for their own reasons.
One key event is the initial skirmish. It's where the misunderstanding between humans and Turians first exploded into violence. This set the stage for the full - blown war.
Fanfiction in the Mass Effect universe about the Alternate First Contact War can be really exciting. It often explores different scenarios that could have happened during that crucial event. Some stories might focus on different character perspectives, like a young soldier's experience during the chaos.
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 Shepard accidentally getting thrown into a dimension where the Reapers are already victorious. They have to find a way to team up with the remnants of different species to reverse the situation. Another could be a dimension where the Mass Effect fields work differently, leading to unique biotic and tech abilities that Shepard has to learn to use in order to get back home.