Does anyone know if there is another dlc like Leviathan. If there is no dlc, does anyone want any questions answered in the game. For me I would like to know who built the crucible and what did the catalyst do that was the same as synthesis?
Any fan of the Mass Effect universe, and the third game in general, would be more than happy for some more single player DLC -- at least I'm positive that I would be.
As for the Crucible, the blueprints were put together by the many civilizations that were harvested during the cycles, and eventually built during the current cycle, in a galaxy-wide effort initially put together by the Systems Alliance, and funded and aided by the other Council and Citadel races as well as other high-ranking individuals and assets that Shepard ran into and subsequently recruited for the effort.
The Catalyst, who was created by the Leviathans, was put in charge of making sure that organic life wouldn't bring doom upon itself by creating artificial intelligence that would "turn on their creators" so to speak, as they had witnessed countless times during their time in the galaxy, at any and all costs. The Catalyst then "betrayed" the Leviathans, and harvested them into the very first reaper, known now as Harbinger. Much like the "synthesis ending", the Catalyst was the first to combine synthetic and organic material into one "perfect" life form, thus beginning the galactic genocidal cycle.