Cerise, Slayer of Fear

First Strike, Lifelink
At the beginning of your postcombat main phase, if you gained life this turn, look at the top {x} cards of your library, where {x} is the amount of life gained. You may cast one of the cards found this way for its mana cost as long as the cost is less than or equal the amount of life gained; otherwise, put that card into your hand.
Put the rest of the cards on the bottom of your library in a random order.