That's mean. :T
The bad thing about the series is that it didn't even get to its highlight.
It only showed the parts that would eventually lead to the climax of the series.
So in short, they were developing the conflict.
(This is just my measly effort to try and defend the main series. Do not mind it.)
I liked how it stopped after
If only they released a third season...
If they do release one, I'm sure that it'll be better than the two previous seasons. After all, the improvement could be seen in Railgun S. I can't deny that Railgun S was the best out of the four.
But still.... nuns.