If you wanted to extrapolate, we could assume that a highly-advanced group of aliens created a powerful AI. Once the AI noticed the cyclical and universal imbalance between organics and synthetics (creator/created), it realized or decided it had to intervene. After the Reapers were created, they harvested organics in order to let new organics exist.From what I got from the story, the game implies there's a more powerful force then the Reaper / Catalyst since they are control by the cycle. Some "Master" entity design the cycle.
We could also assume that the aliens who created that AI/Reapers tried to resist, and they were probably responsible for a blue print of the Crucible.
You mean the created fight the creators. Eh.No one designed the cycle. It just naturally occurs because synthetics are destined to fight their creators.
Probably just the dichotomy of the upper and lower class. Those with power and those without.What evidence is there for it other than the catalyst's saying-so? Javik goes into an example similar to the quarians, yes, but other than that, what evidence are we given that this always happens?