Ninja nuns with rifles and katanas..
I just know that somewhere before they started the production there was a script reading and someone said "mmm.. we already used the g.i joe soldiers in some of the previous movies so how can we make it more interesting?", after zombies, robots, mutants and isis were pitched someone came up with this ridiculous idea.
Perhaps the nuns exist in the source material, but I can't tell since I stopped following the comics somewhere between 52 to Batman RIP because I felt it became too fictitious and unreadable.
Last year I wrote on Jay Olivia's IMDB profile blaming him for creating crap Batman movies, to my surprise he answered and I felt a big shame. Then I answered and told him that he has a dream job that I can only dream of and he should use it to execute his vision rather than doing washed down movies. Jay was kind enough to answer again and he wrote "I don't write the movies I work on nor do I have any control what they are based on. I am an employee of WB animation and I get whatever they assign me.....I am just the Director and I have no say in the design of these shows......don't kid yourself that I have all this so called "Power".
Then I realized that the animated comics directors are going through the same production hell as the live action comics films directors. Jay I am sorry! I have nothing against what you do and how you do it and I believe that I can understand the kind of pressure you are working under.
But eventually, somebody thought that having ninja nuns with rifles is a good idea. He also thought that they will add up nicely to Black Mask, Firefly, Blockbuster, Tusk, The Mad Hatter, Jervis Tetch, Electrocutioner etc... All those names and the stupid villains who stand behind them (and the ninja nuns) are just a proof to how ridiculous the DCU had become.
It seems that DCU today looking is much more Sci-Fi friendly and the storytelling level is based in the comfortable PG13 zone.
I don't know how many decision makers up there in WB actually love comics, I feel that they just want to create more bullshi$ character in order to sell more merchandise.
Personally, I don't think it is a good movie, neither the previous Batman animated movies of the past couple of years.
Even Batman: The Dark Knight Returns didn't reach halfway of it's potential. It wasn't a bad movie but it could have been great as an R-rated movie (and with better casting).
There are very few untouched gems left in Batman published history and I wish that at least one of them ((Arkham Asylum: A Serious House on Serious Earth) ) will get a proper treatment because anything less than R rated will be waste of digital ink.