“Spirit of the Pot of Greed”’s effect does not chain to “Pot of Greed”; instead, you activate it after “Pot of Greed” resolves.
“Spirit of the Pot of Greed” must be face-up on the field to resolve its effect; if “Book of Moon” is chained to “Pot of Greed” or to the effect of “Spirit of the Pot of Greed”, “Spirit of the Pot of Greed”’s effect is negated.
If “Imperial Order” negates the effect of “Pot of Greed”, “Spirit of the Pot of Greed”’s effect still activates because “Pot of Greed”’s activation was not negated.