All of Odin's abilities have names rooted in Norse Mythology and usually refer to one of the many names of Odin; this one however is the obvious exception. Zantetsuken (斬鉄剣) is a Japanese word combined from 3 characters, together meaning "steel-cutting sword". A more literal interpretation would yield "steel-killing sword", implying the blade is so strong that even steel would be defeated by it. It is Odin's signature instant kill move from other Final Fantasy games.