Linking the Horn

To link with the Horn of Mezkeni requires less than one might think in the moment and a lot more in the immediate aftermath.
It is an instrument, and it is magic. As such it is temperamental in the extreme, reflecting the natures of both professions who might have use of it. When the Horn was first created, it could simply be used by anyone. After Zhomek's Inferno, it was decided that perhaps a few restrictions might be put on it just to be safe.
In most senses of the ceremony, it is more of an honorarium than the actual linking. This should have been done over a prolonged period of time and the person should be fully bonded to it already, and the ceremony is more of a formality.
Most of what linking the horn requires is simple proximity and learning the quirks of the device, as is natural. But there is a second, more magical component, that requires the one who wants to link to go through one of the few volcanoes in the world located outside of Prazigal with only the instrument to protect them.
There's also the matter of picking up the instrument in the first place. This is less tied to the Horn and more to the Cult of Zeminek who possessed the Horn for a long time and kept it somewhat locked up. There was a spell they cast on top of their usual booby traps that allowed for a kind of kickstarting of the emotional linking process that would only happen if it was passed on "properly" to the person that their leadership would anoint as per their custom.