Any Elf attacking will always cause it to untap (assuming you didn't already untap it before) and can lead to a very threatening Elf board very quickly.
On Reddit, for instance, u/a-polo damningly stated, is it just me, or this card really sucks? This may seem like a baffling accusation, given the strength of the Power Nine
The Japanese No
Most Expensive Pokmon Card Sold At Auction Is Pikachu Illustrator Promo Hologram Card ($54,970) This card was auctioned off by Heritage Auctions in November 2016, at which time it broke the record for most expensive Pokmon card ever sold at auction
For example, a Charizard 1st edition from the Base Set is worth ~$3,700 ungraded, ~$24,000 with a PSA 9, and ~$167,000 if its PSA 10
I dont see a ton of additional opportunity here, but look for yourself