The lead writer of the first two Mass Effect games has revealed a few ideas he had for tying up the series in Mass Effect 3.
Karpyshyn, who left BioWare just before the completion of Mass Effect 2, admitted the idea "wasn't super fleshed out".
"Dark Energy was something that only organics could access because of various techno-science magic reasons we hadn't decided on yet," he said.
"Maybe using this Dark Energy was having a ripple effect on the space-time continuum.
"Maybe the Reapers kept wiping out organic life because organics keep evolving to the state where they would use biotics and dark energy and that caused an entropic effect that would hasten the end of the universe. Being immortal beings, that's something they wouldn't want to see.
"Then we thought, let's take it to the next level. Maybe the Reapers are looking at a way to stop this," said Karpyshyn.
"Maybe there's an inevitable descent into the opposite of the Big Bang (the Big Crunch) and the Reapers realise that the only way they can stop it is by using biotics, but since they can't use biotics they have to keep rebuilding society - as they try and find the perfect group to use biotics for this purpose.
"The asari were close but they weren't quite right, the protheans were close as well," he said.
"Again it's very vague and not fleshed out, it was something we considered but we ended up going in a different direction."
Karpyshyn was quick to point out that his ending would probably have proved just as unpopular as the game’s actual ending with some fans.
"I find it funny that fans end up hearing a couple things they like about it and in their minds they add in all the details they specifically want," he said.
"It's like vapourware – vapourware is always perfect, anytime someone talks about the new greatest game. It's perfect until it comes out.
“I'm a little weary about going into too much detail because, whatever we came up with, it probably wouldn't be what people want it to be."
Karpyshyn also considered making protagonist Shepard an alien, “but we then thought that might be a little too close to [Knights of the Old Republic character] Revan”.
"Some of the ideas were a little bit wacky and a little bit crazy.”
A final idea was somewhat similar to what the BioWare went with for Mass Effect 3 [spoilers ahead].
"There was some ideas that maybe Shepard gets his essence transferred into some kind of machine, becoming a cyborg and becoming a bridge between synthetics and organics – which is a theme that does play up in the game," said Karpyshyn.
"At one point we thought, maybe that's how he survives into Mass Effect 2."