“Fairy’s Hand Mirror” may not be used to redirect an effect that targets the Graveyard.
“Fairy’s Hand Mirror” may only be used to redirect an effect that has a single targeting aspect that affects a monster on the field.
“Fairy’s Hand Mirror” may only redirect a targeting Spell card to another legal target.
Netrep Q&As:
Q: Does “Fairy’s Hand Mirror” deflect both targeting aspects of “Riryoku”, or only one of them?
A: You could not activate the effect of “Fairy’s Hand Mirror” in response to “Riryoku” because the effect of the “Riryoku” targets more then 1 specific monster. Curtis Schultz, 01/15/2004
Q: Can “Fairy’s Hand Mirror” be chained to “Rush Recklessly” during the Damage Step?
A: “Fairy’s Hand Mirror” cannot be activated during the Damage Step. Curtis Schultz, 04/08/2004