It is actually one of the most useful in my opinion. It cost one but then takes itself out of the deck. With spirit I often pair it with mirror to take the leviathan from 4 to 2 or beholder for a one energy freebee after. With wild I target Broodmother and the beholder for consistency. Trident and glass chalice it is great for clearing the hand. empty hand means double points. It is a permanent -1 on any card. It shines in low cost decks as you cycle through your deck quickly. The minus one is basically the cost to lower an energy of another card. It literally pays for itself as it takes itself out of the deck then every time you use the targeted card it saves an energy. I use it in my wild deck to only have ten cards. When it leaves the deck is 9 then wanderer as a contestant draw plus energy+ and with messenger, Beholder, and Nekomata energy savor aspects I go through the deck many times in a trial. I am averaging 5k a trial.
Holy crap I wrote a lot