When I first saw this card and thought it was rather weak. Now after some consideration this is the card that makes guarded attachments work. Cheating the attachment into play during quest phase after staging gives the player a better idea if they can handle the extra threat and enemy/location. If you are playing guarded attachments this card makes it work.
The King's Return
Action: Search your deck for a Guarded attachment and put it into play. Shuffle your deck.
His harp shall be restrung,
His halls shall echo golden
To songs of yore re-sung
The Fate of Wilderland #147. Leadership.
If you're playing Guarded Attachments and Leadership anyway, then this card not only lets you find the specific Guarded Attachment for your situation, but it's also a deck thinner. Since the Guarded Attachments cost 1 anyway, it's a net cost of 0 (though it does mean you'll be using Leadership Resources instead of whatever you would if you drew and played the Guarded Attachment normally, but that may actually be a good thing, and even allows for playing out of sphere Guarded Attachments). Meanwhile each copy of this, like Daeron's runes, is effectively reducing your minimum deck size. Additionally, as the comment above notes, you can control the timing of the attachment (and thus extra enemy/location) coming into play.
The downside is that there are times you just don't want your Guarded Attachment to pull another Enemy/Location into staging, and this card will just sit in your hand, but if that's a frequent worry then you possibly shouldn't have those Attachments in the deck anyway, with or without this card.