Odin is the head of the gods. He only had one eye. Odin had sacrificed the other eye in Mimer's well to gain wisdom. Odin was the god of war and death, and the Vikings who died in battle belonged to him or Freya.
The dead warriors were retrieved by his handmaidens, the Valkyries. Odin was primarily worshipped by kings, warrior chieftains and their men. It was their needs that he could fulfill.