Kataklysmos

Kataklysmos (Κατακλυσμός, Kataklysmós) was a Sword crafted by Zagreus from the power of the Protogenoi Tartarus and given to his new Lord of the West, the God Kratos, who served as one of his most loyal servants and protector.

As it is linked to Keraunos, the sword wielded by Zagreus, it is implied that Kataklysmos and its siblings are made of the Diamond-like Adamant material found in the Heavens. Fotismos itself seems to be made of a large ruby-like material, and its hilt has two shaped rubies in it.

Trivia

 * Kataklysmos is the Greek word with a number of meanings: "flood", "deluge", and more importantly, "cataclysm".