Shepard chose to destroy Sovereign. The Council then declared war on the SA for that betrayal. The Humans tried to fight but it was a losing battle. Subjugation leading to extinction was not acceptable for making the hard military decision so the Humans chose another path and made a deal with the Reapers. The galaxy and the Cycle would never be the same. AU Shepard makes the rules

A few minor and realistic changes in the decisions made by the leaders of humanity drastically altered the path of Citadel Space and the Reaper War. This is the story of caution and planning over recklessness, the path of the juggernaut over the glass cannon. This is the story of humanity as it should have been. A power worthy of its Council seat, and one the Reapers can't ignore.

When a strange device capable of remarkable feats is found in the Martian ruins, the course of humanity's history changes forever. The resulting leaps and bounds in technology leave humanity well prepared to deal with the rest of the galaxy. AU

The Prothean Ruins weren't. They contained little more than mentionings of an Alien Society; as a result, humanity develops on a completely different path than what was intended, and when first contact is made not with the Turians, but a desperate, destitute race viewed as beggars and thieves, how will this dying race change Humanity? And how will Humanity change the Galaxy? *A/U!*