Using this with a card like Irenicuss Vile Duplication can create incredibly explosive board states
You get Wildcards by opening boosters, competing in events, and winning games to beat your daily and weekly challenges - so if you're short on Wildcards for the shiny new Arena deck you want to build, the best thing to do is get playing with the decks you already have
Ghostly Prison does a great job getting to the late game by making opponents choose between attacking and casting spells and every player wants to cast spells
This means that its not likely that well see them reprinted outside of collector sets that arent designed for regular play such as the controversial 30th Anniversary Edition
Unlike Hearthstone, which only allows players 30 cards, Legends offers up anywhere from 50 cards, which is the minimum to use a deck, to 70, the max
They help win games