Time Rewind

Time Rewind is blue.
When your life total is reduced to zero, instead reveal this card from your hand, then shuffle your hand into your library and draw the same amount of cards. Your life total becomes equal to the last time before you dealt by an instance of damage that reduced your life total to zero.
"I cannot undo the wound but I can undo the bullet striking the target..." - Kell, Weaver of Fate