Never played 1.0, but as far as I know the aciens there were collecting horns similar to Tupsimati for whatever reasons, but they're apperantly "keys".

Whatwe know is that horns in general act like foci, for example: summoners, padjal. Tupsimati (and these other horns probably) can focus and concentrate vast amounts of aether. I'm guessing once things are setup Tupsimati will be summon Zodiark.