Derflinger Emiya

Illyasviel von Eiznbern had survived the Fifth Grail War and was living peacefully with her brother Shirou until a mysterious object appeared in front of her brother. Curious, Illya examined it only to yanked away in a summoning to a Spring Familiar Summoning Ritual to become the familiar of Louise. Days later, Illya and Lousie make a peculiar discovery in a small shop in Tristin.