There are two main types of cards I can think of: creatures with a lot of power, and cards that can boost power
Bill [1st Edition] #91 (Pokemon Base Set | Pokemon Cards) prices are based on the historic sales
MTG Spider Man might not be the most powerful set in existence, but it does have some expensive cards
As you are able to have massive turns where you do loads of powerful things the drawback of bounce only dealing with a thing for a turn is greatly mitigated
Fluttershy works really well with Princess Twilight Sparkle , since most Ponies, Alicorns, Pegasi, Horses, and Unicorns have tails, allowing you to buff your entire board if you build for Twilight Sparkle's kindred ability
Some players revile extra turns as a win condition because it creates an awkward gap between effectively ending the game and actually winning