The Sangheili aren't crazy, they were just misguided in Halo's 1-2

they're actually extremely similar to the Turians, so much so that I was hesitant to ask for it at first. But figured I could play up the differences enough. 

Basically, for them Protheans = Forerunner, they only recently reached spaceflight, (recently meaning 200 years recently, since you said this was an eon after the events of the series) And are a part of the galactic community, though not a council race, roughly in the position humanity was at the time of the series, though probably less desiring for a council seat.

I want my character to be a Spectre, both because it gives me an excuse to be creative with resources and it allows us a lot of narrative freedom. For instance, he could be assigned to a ship that's being sent to Equestria to investigate, perhaps the events of the S4 finale sent off an energy ripple that was detected through the galaxy and the Council is sending an investigation team, kind of like the beginning of ME1, in a way. 

Equestria exists some distance away from a Mass Relay, and the princesses are "aware" of space but do not see a reason to explore it. And they are unaware of the relay connecting to other systems and the galaxy as a whole, thus the beginning can be introducing Equestria to the galaxy at large (whether against interference protocols or not) 

So yeah, now we need a conflict I guess.