Who is Igneous Cutwell from Mort and what is their importance?

Igneous Cutwell is a wizard in Sto Lat. His crystal ball is cracked; his astrolabe has parts missing; there is a scuffed octogram on the floor, and the obligatory stuffed alligator hangs on the wall. When Mort visits Cutwell, he assumes Mort wants a "love philter". Mort, however, wants to know how he is suddenly able to walk through walls.