We are now provided with an explanation fopr most of the mysteries presented so far. Where does Kagari come from and why was Amadeus created. While the solution is complex and convoluted, it's a reasonably consistence solution. There are some question, such as why was there a Rebel organisation in the WW3 world. This was a feature of the SERN world. The main issue is its sheer complexity and the fact it has taken us 18 episodes before we understand all the pieces. I understand the main point as this complex background gives Okeba a clue on how to solve his primary issue, although it will probably take a while before he realises it.
The other issue is the episode construction, its filled with moments of intense action and then it seems time stops and a long conversation occurs, before the action begins again. This type of structure was not used in the 1st season and is rather annoying. It would be better if the action occurred and an explanation occurred later, or as did occur in some pauses, once side has the other under control so a conversation could occur. It's a melodramatic and lazy structure, but I must admit it works.