He unfolds the cloth first, revealing the medallion hidden within. The face that peers back is profane and vulgar, but it is not unknown to him. It is the sigil of a creature whose existence has long thought to be past but whose influence garners followers even now.
The Priest uses the cloth to pick up the medallion, careful not to allow any part of his flesh touch the unholy metal. He seats it into a slot in the pedestal designed for just such a purpose, then he casts the cloth to side.
The box itself he places on the pedestal so that it sits before the medallion. The eyes of sigil seem to leer at the box, the lolling tongue almost to lap at the box as if to sample its contents.
The Priest runs his fingers along the edges of the box, traces of smoke trailing behind, outlining it in a grey haze. Finally, he places his index fingers on either side of the box and whispers three words — foul and vile — and the medallion begins to glow. The box opens with a snick! and smoke flows out from the narrow seam.
The Priest lifts the lid away from the box and sets it to the side. The smoke inside the box swirls before him like an angry storm but remains in place for the moment. He dips a finger into the smoke, drawing out a long tendril of grey vapor. Then, with his other hand, he twirls the tendril around his index fingers, allowing some of the smoke to climb up his hands and disappear up under the sleeves of his robe. The smoke reappears again above his collar, wrapping around his head and face. His pupils dilate until his eyes are totally black, then return to their normal color. He grins, a toothy, malignant smile, then releases the smoke back to the box.
The medallion, still glowing with an ominous, green, sickly pallor, suddenly draws all the smoke from the box. The smoke surrounds the medallion, hiding it from view. It once again resembles a small, angry storm cloud, lit within by an eerie green light. Static charges shoot off the medallion like tiny lightning bolts, further enhancing the illusion of a storm.