The anime ends without explaining several key mysteries, which are later clarified in the Light Novels:
The finale of Mahou Sensou (Magical Warfare), Episode 12, is widely known for being one of the most confusing and abrupt cliffhangers in anime history. Mahou Sensou Episode 12
Takeshi and Gekkou engage in a final showdown. During the fight, it is revealed that their mother actually asked Bishop to kill Gekkou years ago—a revelation that shatters both brothers' previous understanding of the accident. The anime ends without explaining several key mysteries,