I’ve made an insane discovery, Eda is actually based on a female vampiric demon from Slavic Folklore called the Strzyga. 

The creature is said to start as humans with grey skin, two rows of two (the 2nd row barely visible), two hearts, and two souls. But as they live on, they obtain owl-like features such as claws, eyes, feathers, and wings growing out of their backs. Strzyga assume this monstrous form after they die, as one soul would ascend to the afterlife while the other reanimated the body. The Strzya would fly through the night, hunting humans and animals alike to drink their blood and devour their innards. Preferred victims being those who had wronged them in life.

This takes Edas’ statement “Every myth you humans have is a result of a bit of our world leaking into yours” to a whole new level.