THE EPIC OF ZEKTBACH

The story begins when the kingdom of Noigllado suddenly invades the small country of Azuelgatt and brings it to the brink of destruction. General Adnowell leads Noigllado's troops against Azuelgatt's final, remaining line of defense: the fortress Doroah, led by a skilled female warrior named Shamshir. (Source: Anime News Network) — Description from AniList community (anilist.co).