Hows this for an alternate ending? How bout at the end you are given a fourth choice, Which basically amounts to telling the star child to Go To Hell (Maybe 2, One is a polite "Would you kindly sir go to hell" and the other is perhaps punching the kid in the face..)
Then Shepard delivers some form of "Reason you suck" speech to the starchild, Saying that as he just pointed out, we dont need you anymore, We dont need the reapers, We can stand up for ourselves and dont need a god to sit here and "Save" us from ourselves... The starchild gets angry, revealing he is Harbinger, and that the choice was because you have become a major nuisance to his plans...he wanted an easy way to dispose of you.... You can reply something along the lines of "So in other words, You are scared of us" Harbinger hesitates, then responds "... We fear what you may become"
Then depending on your war assets things play out a couple ways... Way one is for max assets, 6500 or higher with 90% readiness.... it will ha