If the target player has fewer cards in hand than the number of cards they're instructed to reveal, they reveal all the cards in their hand
When you discover X, you reveal cards one at a time from the top of your library, so any cards that do not meet your discover value of X become the rest and essentially get shuffled before you place them at the bottom of your library
Trading big creatures in for cards and more permanents snowballs quickly, especially once reanimation spells come into play
Shadowheart, Dark Justiciar Shadowheart, Dark Justiciar s ability to sac a creature and draw life equal to its power is one of the few black draw cards allowing you to draw an X amount of cards and not pay life for it
However, you can activate the ability of one creature in response to activating the ability of the other creature
Shuffle up to four target cards with mana value 3 or greater from your graveyard into your library