I know IT isn't really but its a shame that Bioware didn't use Indoctrination for the Reapers to stop us since we were the ace in the hole to ending the Reaper Threat. I mean the Reapers tried to stop Shepard by killing him and the Illusive Man undid that by bringing us back to life. So in a sense it seems absurd that the Reapers didn't try to Indoctrinate Shepard at all. "yeah lets indoctrinate everyone that can't stop us but we the almighty Reapers just don't have the heart to indoctrinate the one person that can stop us. Challenge Accepted" I mean when you sit down and think about it, the main character not getting indoctrinated by the Reapers is just absurd. It means the Reapers aren't completely controlled by the Catalyst or the Catalyst was a last minute throw in to the game. Reapers show signs of having an ego and that is the only explanation at best for why the Reapers didn't resort to indoctrinating Shepard, but wait if Reapers have egos than how can they be controlled by some ominous Catalyst because if they are controlled than they essential wouldn't have egos that would be counter productive to what they are trying to do.
So IT being created was only the results of Biowares mistakes. The mistakes is as followed:
1. Why did the Reapers not Indoctrinate Shepard to stop him/her? The Indoctrination of Shepard would've meant the Reapers total victory over the Galaxy. Shepard not being Indoctrinated can mean that the Reapers thought of him/her as a challenge so that would mean the Reapers have egos.
2. If the Reapers didn't Indoctrinate Shepard than how can the Catalyst exist? Catalyst actually existing means that the Reapers would've indoctrinated Shepard to stop the war effort against them or eliminate Shepard again. I am more incline to believe the Reapers would've indoctrinated Shepard to stop the him/her from rallying the Galaxy up. Reapers not doing the logical thing by Indoctrinating Shepard probably shows signs that they have egos, they wanted to show Shepard that all his/her efforts were for nothing by crushing the united Galaxy. Reapers had many chances to Indoctrinated Shepard too but choose not to, the logic of a Catalyst controlling them is ever so nonexistent.
3. Catalyst is a last minute add and we see this throughout the series, we see that the Reapers have egos because if they didn't than why did they play around with Shepard.