Well, it could be about humans and reapers teaming up to fight a common enemy, like an even greater evil from another dimension. They might combine their unique skills and technologies to achieve victory.
Maybe a human scientist who has studied the reapers for a long time could be one of the main characters. He discovers a way to make the alliance possible. And on the reaper side, a young reaper who is more open - minded than the others and is willing to work with humans. The two of them could be the central figures in the fanfiction, with their relationship growing as they face various challenges together.
Well, the plot could be that Naruto has the powers of the Grim Reaper. He might be in charge of collecting the souls of the dead in the Naruto world. Maybe he uses his new powers to judge those who have committed great evils during their lives in the shinobi world.
One benefit could be sharing of technology. The Eldar have advanced psychic and technological capabilities that humans could learn from. For example, their way of using psychic powers in a more refined and controlled manner compared to the often dangerous and unpredictable human psykers. Humans, on the other hand, have large numbers and a certain tenacity. In a fight against a common enemy like the Necrons, this combined strength could be a great advantage.
A possible plot could involve a time - traveling aspect in the 'human first contact reaper fanfiction'. A future human, who has seen the destruction caused by the Reapers, travels back in time to the moment of first contact. This person tries to use their knowledge of the Reapers' weaknesses to stop them from ever establishing a foothold on Earth, but they have to deal with the disbelief of the people in that time period.
One possible plot could be that Harry discovers he has the ability of a Soul Reaper. He then has to balance his life at Hogwarts with his new - found duties as a Soul Reaper. For example, he might have to deal with Hollows (evil spirits in Soul Reaper lore) that are lurking around the Forbidden Forest.
One idea could be a story where a group of humans and Covenant members are forced to team up against a new, greater threat that endangers both their species. Maybe a powerful alien race that neither has encountered before.
A military officer could be the main character. During the first contact with the Reapers, they are in charge of the initial defense strategies. They have to make tough decisions about how to deal with the unknown threat, and their leadership skills and military training would be put to the test as they try to protect humanity from the Reapers.
The plot might involve the goblins approaching Harry Potter for help in protecting their underground kingdoms from a new threat, like a horde of dark creatures. Harry, being the hero he is, agrees to form an alliance. They then train together, combining wizard magic with goblin technology and combat skills. This alliance not only helps in fending off the threat but also makes the wizarding community re - evaluate their relationship with the goblins.
In fanfiction, a human and geth alliance might form due to a special event or individual. For instance, there could be a human scientist who has been studying the geth for a long time. This scientist discovers a way to bridge the communication gap between the two species in a more profound way. Through his efforts, more and more humans start to see the geth in a different light. At the same time, some geth programs also show an interest in working with humans. As a result, an alliance begins to take shape. The process might involve negotiations, cultural exchanges, and the building of trust between the two parties. It could be a long and difficult journey, but the potential benefits of the alliance, such as technological sharing and mutual protection, make it worth the effort.
One idea could be that the alliance forms due to a common threat from a new, even more powerful enemy. For example, a third alien race arrives on Sera and starts to decimate both human and locust populations. The two groups are forced to put aside their differences and combine their unique combat skills and technologies to fight this new foe.