Mnemonic Sliver

First strike W: Target creature gains first strike until end of turn.

Flying Whenever this creature becomes the target of a spell or ability, this creature gets +0/+3 until end of turn.

Buyback 3 (You may pay an additional 3 as you cast this spell. If you do, put this card into your hand as it resolves.) Prevent the next 3 damage that would be dealt to target creature this turn.

All Sliver creatures have "2: This creature gets +0/+1 until end of turn."

Flying

Sacrifice an enchantment: This creature gets +2/+2 until end of turn.

Flying When this creature dies, you may put it on top of its owner's library.

1: The next time a black source of your choice would deal damage to you this turn, prevent that damage.