LittleCrow

In the early 21th century, Earth came under attack from the alien Azo, who creep their influence across the globe over the course of the next few decades. That initially means little to a young Renton Thurston, however, who delights in hanging out with the sunlight-averse girl Eureka and Nirvash, a cutesy little critter who will one day grow into a transforming mecha-like being.

When he was young Shirou had lost his parents in a large and unexplained fire. He was rescued and later adopted by a man named Kiritsugu Emiya who had revealed to Shirou that he was a magus, a person capable of using spells and magic.