Ame, the Split Second

Ninjutsu {1}{u/b}{u/b}
Whenever Ame, the Split Second does combat damage to a player that player puts the top half of his or her library, rounded down, into his or her graveyard.
Whenever another creature you control deals combat damage to a player you may pay 5 life. If you do, return Ame, the Split Second to your hand.