The Third: Aoi Hitomi no Shoujo, World Destruction: Sekai Bokumetsu no Rokunin Recommendations
Both anime dealt with two enemy groups of humanoids and how the conflicts that exist between them could mean the end of the world. The character of the story is also set up to be the same. A strong woman who have a strange encounter with a mysterious man. In the end, the true identity of the man she met is revealed which will decide the fate of the world... the end, or the beginning.