I think this can be one of the best Guarded attachments around. Easy to include since it's neutral with a basic but powerful effect of readying in most decks. But in some dedicated decks like Dwarf mining or (even better) Three Hunters Contract ones it can become amazingly powerful. Combining it with Gimli and The King's Return is quite possibly the best combo.
Ring of Thrór
Guarded (enemy or location).
Attach to a Dwarf hero. Action: Exhaust Thrór's Ring and discard the top card of your deck to ready attached hero. If the discarded card is an attachment, put it into play.
The Ghost of Framsburg #93. Neutral.