Attacks » Flare Destroy
If the Defending Pokemon doesn't have any Energy cards attached to it, does Typhlosion's "Flare Destroy" attack still require Typhlosion to discard an Energy from itself?
Yes, if the attacking Pokemon has any Energy cards attached, it must discard one of them.
Source: HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)
Attacks » Flare Destroy
When I use Typhlosion's "Flare Destroy" attack, which player chooses the Energy card to discard from the Defending Pokemon?
The player that used the attack gets to choose which Energy cards get discarded from both the Active and Defending Pokemon.
Source: HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)