Daemons of the Shadow Realm

Yuru, a skilled hunter, lives in an isolated village with his twin sister, Asa. She's been locked away for years, forced to perform a specific duty that limits her interactions. The village is attacked by armed men in helicopters, known as "dragons," who kill all the adults. Yuru tries to reach Asa, but finds her lifeless body instead, and the killer claims to be his true twin sister. A man named Dera intervenes, saving Yuru, but they're soon cornered. Dera has Yuru give a gift to the village deity, summoning daemons that expose the truth behind the village's destruction.