There are 51 unique new cards spread across the five decks (some cards appear in multiple decks)
If this spell was kicked, it deals 4 damage instead
Each of those decks even contains two unique Bobblehead artifacts, all of which have different effects that get more powerful the more Bobbleheads you have out - for example, the Luck Bobblehead in "Hail, Caesar" lets you roll dice to make mana-generating Treasure, but will even cause you to win the game outright if you manage to get enough Bobbleheads (either by copying them in creative ways or mashing the Fallout cards together into a custom deck) and then roll absurdly precisely
It's not the end of the world if you lose these cards early, and both Hades, Lord of the Underwold and Part Of Your World will allow you to pull them out of your discard pile if you really need them, but consider holding onto these two cards if you have other two-cost cards to play, like Yzma, Alchemist, until you can put the combo together