Keres and Valkyries
It is possible that a connection exists between Keres and the Valkyries of Norse myth. Both deities are war spirits that fly over battlefields during conflicts and choose those to be slain. The difference is that Valkyries are benevolent deities in contrast to the malevolence of the Keres, perhaps due to the different outlook of the two cultures towards war. Also the Greek word "keres" (choice) and the Old Norse word "kyrja" (to choose) from "valkyrja" seem to have a common root.
Read more about this topic: Keres (mythology)