I'm considering whether to include this in my deck or not. Attached to a powerful hero it can certainly make a difference.
But I don't suppose it combos with Boromir's or Caldara's ability? The wording on the heroes are, I think, "discard" while FoGG requires the hero to be "destroyed" - not generally "leave play". Otherwise it would be a very powerful combo with Boromir - dealing 2 damage to multiple enemies and then lowering your threat by 11.
I'm not sure it's worth building around, to me, but one strategy could be to attach it to a hero of a high-threat player if you have Landroval or Fortune or Fate available. Elrond would be the most effective, if you don't already have several attachments or resources on him.
Edited by Olorin93