I imagine a mirrorIndorani would be summoning things from your Nightmares type of thing. When I think a little bit harder on this, I can't help but picture the original Ghostbusters movie and some hapless Aetolian summoning the Staypuft Marshmallow Man equivalent, like a giant humgii or something.
Ivoln erupts destructively from the ground, His body shedding sand and clay. The hole left behind....
Ivoln rolls His shoulders, gaze settling upon you. "Take this," He imparts with a nod, and little else.
Ivoln gives a perfectly round black stone to you.
Ivoln mightily stamps the ground, forming a huge gash in the earth, through which He drops. The tear closes itself, leaving no trace of the God's departure.
You say, "Thank Y-."
(Bloodloch): Ivoln says, "I've given a stone to one of your fellow citizens. Find the citizen that carries it, and convince them to give it to you. If you are successful you will wear My blessing."