When you pay for encore, you exile the card and create tokens equal to the number of opponents you have and then attack them if able, and the tokens are sacrificed during the next end step
This card was given out in random packs to participants in the 2020 Pokemon Card Gym Tournament in Japan only for a very limited time, from July - September, 2020
You wont always be the most powerful player, but you will almost certainly be the one having the most interesting time
That means that you can get to turn five, tap five creatures and then cast this for five mana
In addition to Dittos current confirmed transformations, there is now a chance that the following Pokmon will instead be a Ditto when you catch them
They are: 5 * Ivysaur Sticker, 1* Nanab Berry, 1 * Hyper Potion 5* Charmeleon Sticker, 1 Razz Berry, 1 Revive 5 Wartortle Sticker, 1 Pinap Berry, 1 Super Potion 5 Blissey Sticker, 1 Golden Razz Berry, 1 Charged TM 5 Meltan Sticker, 1 Pinap Berry, 1 Fast TM 5 Pikachu Sticker, 1 Rare Candy TCG Shirt & Hat 1 Egg Incubator