In Ptolemy's Gate, Faquarl says that Nouda would welcome the attack of the staff and feed off of it. However, when Bartimaeus observes Nouda, he is destroying his protective body from containing too much power from feeding off of the commoners. Could not Bartimaeus and Nathaniel continuously fire the staff at Nouda until his body simply disintegrated and then destroy his far less protected essence?
Sincerely yours,
Matrim Cauthon
Hello Matrim,
It's true that Nouda's protective shell is fast disintegrating, meaning that he's no longer shielded from the pain spirits feel when they're in our world. However, the destruction of Makepeace's body (which has essentially happened by the end of events in the Glass Palace) doesn't result in Nouda's essence being weaker or more vulnerable to destruction itself. In the ordinary way of things a spirit's essence is naked when they come to our world; in Nouda's case that naked essence is now hugely, ravenously, terrifyingly potent, and the pain it now feels only adds to its rage. In the circumstances B and N adopt the only plausible strategy for destroying it.
All the best,
J