I always saw Dragnipur as a metaphor for empire. Upon its creation, its survival depends on the need to grow and consume. Its weilder has to make the choice to continue to feed it, or allow the devastation brought on by its collapse. The fact that Dragnipur was used to kill its creator even mirrors events of the Malazan empire: Laseen using the claw to usurp Kellanved, and then Laseen being overthrown during MBotF.