also: いいきのおに
expression, noun
person who died in a foreign land; ghost in a foreign land
Idiomatic expression for someone who died away from their homeland, often with a sense of pity or loneliness. The literal meaning is 'demon/ghost of a foreign land'.
彼は異域の鬼となった。
He died in a foreign land.
戦争で多くの人が異域の鬼となった。
Many people died in foreign lands during the war.
Compound of 異域 (foreign land) + の (possessive particle) + 鬼 (ghost/demon). The expression likely originates from classical Chinese literature, where dying away from one's homeland was considered a tragic fate.