Hylda of the Icy Crown's ability will trigger only when an effect instructs you to tap an opponent's creature
Set size: 72 cards Cards per pack: Hobby 8, Blaster 8 Packs per box: Hobby 36, Blaster 11 Shop for 1999 Topps Pokemon: The First Movie boxes and packs on eBay
When you use this move you have to flip a coin, if you get a heads, Snorlax and the defending Pokemon are asleep, if you get a tails Snorlax is asleep
Shimmercreep, on the other hand, is just okay
Its highly likely the company wont ever release any new Pokmon Master Ball Mirrors in the future, hence why it goes for more than most of the URs, SARs, and SRs in the setlist, starting at ~US$223 on the SNKRDUNK App
This is infinitely better than letting your opponent hit you first to fulfill this condition