If “Imperial Order” & “Necrovalley” are both active, and “A Cat of Ill Omen” is flipped, you add the card to your hand because “Necrovalley” is face-up on the field, even though its effect is negated.
If “Mystical Space Typhoon” is chained to the effect to destroy “Necrovalley”, so that “Necrovalley” is not on the field when this effect resolves, you cannot place the card in your hand.
You select the card for this effect when the effect resolves, not when it activates.
Netrep Q&As:
Q: If “Pharaoh’s Treasure” has been successfully placed in the Deck face-up, can the effect of “A Cat of Ill Omen” be used to place it on top of the Deck?
A: Yes you can. The “Pharaoh’s Treasure” would be placed on top of your Deck. Its effect will activate when it is drawn. But if there is a “Necrovalley” face-up on the field, the “Pharaoh’s Treasure” would be added to your hand right away and would NOT activate its effect (because it isn’t drawn). Curtis Schultz, 04/07/2004