I do recall reading something like that:

Make an Adamantium Long Sword. Alchemist uses some concoction and now it's a Blessed Adamantium Sword. Spiritbond, combo materia, love it at the inn, drown it in the blood of a thousand lalafell bandits, etc. Submit to NPC. Your sword is renamed "Excalibur". *something* like that is what I thought I read.

Minus the part about bandits. Any lalafell will do.