Does the new Staff even need runes? It was given some in FR. However, in WGW we read on page 460:from the GI wrote: "Now, of course (I mean after "The Second Chronicles") *all* of Kevin's lore has effectively ceased to exist. (Linden's new Staff of Law doesn't even have *runes,* for crying out loud.)"
"Living Law filled the bands of lore; living power shone in
every fiber of the wood. The old Staff had been rune-carved
to define its purpose. But this Staff was alive, almost sentient:
it did not need runes."
As a synthesis of two beings, one a being of pure Earthpower, and the other "had been so perfectly made that he attained the stature of natural Law," the Staff of Law did not need runes.