Drops from Ironclad Severer in Abyssea - Misareaux!
Its a 100% Drop from the NM, who is easily low-mannable, through multiple means including Chainspell Zerg (Though, this method has brought about some strange behavior in the mob i cannot go over), or Kiting/Nuking.
Its a simple NM as long as you don't have multiple people standing in range of his AoE normal attacks.