If you're looking for manga similar to Blade Sangokushi Gaiden, you might like these titles.
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.
A tribute, showing some highlights of the past of the legendary Red Comet Char Aznable
Yamato is a small country at war with the military might of Mars. In the face of this overwhelming superiority, Yamato's defeat seems inevitable. Even on the island of Gallé in the South Pacific Ocean, where fierce battles are also being fought, Yamato's army is in a state of collapse. Sergeant Tatsumi fights for the survival of his regiment, which is in a desperate situation. One day, just when all hope seems to be gone, he sees an "object" named Kitetsu drop from a transport plane...