Hmm, well, actually you might be right after all, that was the first line in Atrus's prayr
But then again it is possible he intended to write it like "I am D'ni's Atrus"... I dunno.
I think you should just ignore what I said and stick with what you have. Or maybe post on the guild of linguist's board, they would know what to do here
EDIT: After doing some more reading, it seems teh would be "with" in this case. So it is between "D'ni's Escher" and "Escher with D'ni", so I think you were right after all. Oops, sorry