The power structure of the trigger words used at each progression seems unnecessarily constrained. Of course, the original crafter... or crafters as the case may be... clearly limited themselves to First Circle power levels. But why? Why not imbue the spell with Second Circle power, find a suitable six, seven, eight, nine or ten-syllable trigger, and increase the number of missles accordingly? It appears to be child's play, but a couple weeks in my study should enlighten me to anything I've overlooked. Of course, that would mean we'd have to stop travelling and Dreaming for two weeks. Not very likely... Ha!