Quote Originally Posted by Daralii View Post
Wasn't Zantetsuken brought to Eorzea by an au ra?

I have to think it's an eikon, and Odin is a primal summoned by it.
As Koji explained, Odin was an Allagan warrior who was heading to Eorzea to save Urth (who was not the Allagan hero we thought she was, at least to the Allagan royalty), and during his travels he found Zantetsuken and it consumed him (more or less). He ended up killing Urth, and was later sealed by Wiyu.

So... He found Zantetsuken somewhere between northern Ilsabard and the Shroud on Aldenard. The sword may simply have a traditionally Doman name and so everyone assumed it was a Raen weapon, but it is stated to be an Eikon, so I doubt it was created by anyone of this world.