Heim (ハイム Haimu) is a character from the background story of Fire Emblem: Genealogy of the Holy War. He is one of the Twelve Crusaders, possessing the title of Saint (聖者, Seija), and is the original wielder of the Book of Naga. He was known as a "powerful military hero who saved the world". Saint Heim is the founder of the country of Grannvale, alongside its capital, Belhalla. While his blood lineage is known as Naga in Genealogy of the Holy War, it is called Heim in Fire Emblem: Thracia 776 instead.
In Norse mythology, Heimdall was a god who was prophesied to fight Loki during Ragnarok.