Everyone has at least HEARD about the original Dark Energy ending, but other than a few odd details there's not much we really know about. However, recently Drew Karpyshyn in an interview with the Escapist has decided to shed a little more light on this discarded plot point. The interview delves more into HOW exactly the Dark Energy is harming the universe and why humanity is so important to the Reapers. Along with the Dark Energy plot, Karpyshyn also mentions some more fantastical early discarded endings such as Shepard actually being an alien or Shepard becoming some sort of cyborg in order to link the synthetics and organics. While not the most developed (Karpyshyn even says it was somewhat early in development), I still think the Dark Energy plot is an interesting idea. Sound off in the comments if you want to share your opinion on this discarded ending.
If you want to see the full interview, head over to the Escapist by clicking the link here