Player Update: I just recently unlocked the Machined Warhorn, the one that says it needs to be purchased for ores in Dragon Stand. Its a mini collection you need to complete before you create the actual item Machined Warhorn, but i was awarded with both Machined Warhorn achievements for unlocking the one. Hopefully this helps! The only one that is truly bugged is the “Complete a Magus Falls map with an elementalist” Other than that, all of them are acquireable.