If you're looking for manga similar to Senjou no Mahoutsukai 0, you might like these titles.
In the year 1939 an unknown enemy called the Neuroi appeared. Their purpose is unclear and origin is unknown, but they attack and destroy any signs of human civilization they come across. Because conventional weapons are useless against them, humanity developed a striker unit known as the Strike Witches to combat the Neuroi. Miyafuji Yoshika is a girl with exceptional healing power but lacks control; she has been scouted to join the Strike Witches and fight the Neuroi, but all she wants to do is take over her family clinic. After witnessing an attack by the Neuroi on her way to find out if her father is still alive, Miyafuji resolves herself to fight for and protect the people around her. Who or what are the Neuroi and what do they want?
Glas loses his path in life when he pulls a "flop" during his spirit summoning ceremony. However, he is given another chance when he receives a royal order to fight in the front lines, along with the Princess's knights, as a war doctor. With his "flop" capable of curing anything, the curtains unfold upon a new fantasy war chronicle!
It has been nearly twenty years since the last Great War, and while smaller skirmishes are still taking place across the world, peace is mostly the norm. In the Fuso Empire, Sakamoto Mio is about to join the war effort against the Neuroi alien invaders. She will have to distinguish herself among the other hardworking cadets if she is to become a full-fledged Strike Witch. Soon, she will have the chance to prove herself in battle, as the Neuroi launch their latest brutal attack.