HellishFiend wrote...
I'm still of the opinion that the whole "Crucible + Catalyst = Defeat of the Reapers" thing is very doubtful, but we'll see.
I agree

As I said before, I still think the
Crucible is a Reaper device "used "in case a Cycle has become too dangerous. "Dangerous" doesn't necessarily mean that the Cycle would be able to defeat the Reapers. But it means that this Cycle might be able to inflict some serious losses on them.
EDI said that "self preservation" is one of the Reaper's key motives - if not THE key motive. So I believe taking heavy losses is something they would try to avoid at all costs. And we can be sure, that the united galaxy of "our" cycle would be able to do so in the final battle about to take place. Remember in a normal cycle there would not be a final battle, since the Reapers would take control over the Citadel AND the Mass Relays immediately. It would simply not be possible for the organics to gather all their fleets.
As for the "
Catalyst" itsellf I'm still not 100% sure what it could be (but I doubt it is the Citadel or the Starchild

)...I have a few thoughts on it though. But they aren't well thought through yet to be honest...it is more of a quick brainstorming:
As far as I can tell from the word, a "Catalyst" normally
enables, speed-ups or directs a reaction. So if the Crucible is some sort of Reaper trap, maybe sending out some sort of Indoctrination signal, the Catalyst might be something that enhances this very signal. As Indoctrination ultimately breaks someones will, a huge Indoctrination Device might need someone strong-willed as a "Catalyst".
Maybe THAT is the reason why the Reapers try to indoctrinate Shepard. If this "remarkably strong-willed" person would "fuel" the Crucible, the signal might be strong enough to indoctrinate all organics in a certain area. Avoiding the losses of a final battle.