It - stabs at his heart, again, is the point of this subplot about how, it's going to seem, at first, like this place is his new home, not Osirion, this is the fragment of dath ilan, the Temple of the All-Seeing Eye, and then he's going to look into it and it's going to be horribly Wrong somehow and - maybe this is how he loses Ione, too -
Keltham shall Prestidigitate the air into diffraction-sheened fragile shards, then, and send them wafting over to cling to the sand art while they last, outlining the words in strange rainbows that change color depending on the angle you look at them. He also moves his sparkles, from thirty feet, with Mage Hand.
(He has that wizard spell hung, for now, though he'll need to swap it out for Detect Magic if he stops being a cleric. And give up Resistance, and Guidance, because Prestidigitation and Message and Detect Magic and Dancing Lights are none of them spells he can afford to give up...)