According to MAL there are 13 episodes, so one more to go although I am not quite sure why they couldn't end it in 12 given the ending of this episode.
That said this episode is triggering me. Even for Symphogear the amount of complete randomness was staggering. Apparently Hibicocoon stood dormant for two days. Guess they needed the time to bring Miku there. Genius armed forces, what did you expect would happen if you fire conventional weaponry onto a supernatural and most likely hostile being? Of course it will retaliate with far superior power. It was pretty funny that out of all places they inserted the anti-linker into her ass. Miku is our lord and savior yet I am shaking my head for their ace in the hole to be yelling at Hibiki. Typical America fires a missile onto an already resolved situation. Alchemists to the rescue, so they actually can be useful. At this point however out of absolutely nowhere they start singing. While their song is really nice it completely comes out of left field. Adam finally gathers the divine power only to ruin it first by making the unbearable pun and then by having Tiki tackling him (really?) while Hibiki punches it out of existence. After this the episode just cuts off and rolls the ED
This episode and by extension the whole season had potential but if suffered from abysmal writing.