Mass Effect 3 ending drama is now a decade old and the recent AMA from one of the biggest BioWare writers showed a different way it could unfold.
Back in 2012, we were getting ready for an epic conclusion of a beloved series that took us on an unforgettable ride through space where we got to see wondrous new places, meet iconic individuals and try to save it all from an incoming, seemingly unstoppable, threat. What we got in the end, was a nonsensical explanation why the Reapers were around in the first place and a non-ending with different colours, followed by a brief message that said "ME3 will get DLC, buy it. Peace out".
The damage from this slap in the fans' faces was somewhat mitigated with the extended cut DLC but the fact that the story and ending weren't fleshed out enough to be pushed to store shelves was clear to everyone who jumped into the trilogy and finished it. Now, a former BioWare writer shed some more light on what the story could be like, as well as an ending that never made it to the final game.
First, the story about Reapers' motivations has been known in Mass Effect community for years, known as the Dark Energy theory. Basically, the use of Mass Effect relays was creating energy that ended up shrinking the universe and Reapers were seeking a way to stop it from happening, leading to the harvest of advanced civilisations and their knowledge every 50,000 years.
Only seeds of this story made it to the game and you can see it when Tali mentions a star that is aging rapidly in Mass Effect 2. Before ME3 released, Karpyshyn left the studio and his ideas for the ending remained at the grassroots level.
One such idea was unearthed during the aforementioned AMA on Reddit and it involved a way to deal with the Reapers without getting every race in the galaxy stuck in the Solar System.
" As for Mass Effect, we has some very rough ideas planned out. Basically, it involved luring the Reapers through the Mass Relays then detonating the entire network to wipe them out... but also destroying/damaging the relays and isolating every galactic community from the others. But we still had to figure out a lot of the details, and there were some issues with that option... like what we would do in the next series of games. "
In this ending, it appears that not all the navies in the galaxy converged in one spot to stop the Reaper invasion but the races sprung a trap on the reapers instead. They ended up isolated but it is still much better than what we got before extended cut when the Mass Relays were outright destroyed and everyone was stuck.