As of now, I'm leaning toward Nay. You're attaching an energy to a Pokemon you want to retreat and it doesn't even reduce the whole cost. If you attach it to Trevenant, you'll have to discard it. The only combo it works with is Wobbuffett as you can switch into it and still attack with dimensional valley. But even there it's a liability thanks to enhanced hammer. With cards that punish you for using special energy, it doesn't do nearly enough to justify putting in decks. Personally, I'd rather use float stone or switch.