User blog comment:James12708/Possibility of a Mass Effect 4/@comment-5687135-20121031201025/@comment-5212406-20121031223450

Well actually the refuse ending pretty much loses the war. You don't win because your cycle is exterminated but the next cycle survives and wins because of what liara left behind. There is no narrow victory they've stated the reapers cant be defeated conventionally hence why the crucible was built.

As for synthesis, nanites are inside every thing so im guessing when a species reproduces nanites are transferred into the offspring and multiply similar to cell growth.