The Ubermensch said:
Black, but I don't think you're right about synthesis.
We can talk about what they said and what happened for eons, but you have to look at the ending as a separate beast. Besides which, star child said "We've tried synthesis but it always failed". Take it at face value, what is he asking?
I think he's asking for the singularity; not just the technological singularity but the Omega Point. "To remove the barriers to understanding so that peace and reign eternal". But the instant you completely understand someone else, I'm not going to say that individuality is gone; but questions are answered. A lot of questions... Picard, help us out here
http://youtu.be/Xh_t2fFF3B0?t=7m8s
Also, I stand by my Light Yagami comparision, reason being in both Death Note and the Control ending the protagonists are the sole authority. Shepard now has direct command over the most powerful death fleet in the universe and answers to no one, Light can determine the fate of everyone on the planet and answers to no one. The UN is a council in theory and everyone on that council is supposed to hold everyone else accountable.
The only difference between Shepard and Light is behaviour, but they are basically in the same position.
Except the catalyst isn't Shepard. As far as we can tell, one of two outcomes are likely:
-Shepard killed himself to imprint his personality and physical look onto the catalyst
or
-Shepard "became" the catalyst, but in doing so destroyed his own humanity in which case he is no longer Shepard, and is simply the catalyst with a new mission statement.
No matter how you slice it, Shepard dies in the control ending, what remains is something else.
This might be a matter of semantics, but the real comparison should be between Light and The Catalyst.
EDIT:Also let's not forget that (for what it's worth) The catalyst in the control ending during the extended cut, clearly differentiates between Shepard and itself.