"Right, right. Although I suspect luring the Null along to another world may not go so poorly if the right one is chosen. Aren't there worlds here where people have advanced knowledge of machinery? Just because these fools couldn't figure out a solution doesn't mean other places can't."

In any case, the Null don't seem like that much of a problem to Caedra. It seems they simply want to be left alone, away from the influence of the gods. So, then - kill the gods, gain control of the Door, and everyone is happy. Left in isolation, the Null may well turn to invading other worlds, bent on wiping out emotion-expressing people throughout the multiverse, but it won't be her problem any more.