Spellstutter Sprite

Flash
Flying
When Spellstutter Sprite enters the battlefield, counter target spell with mana value X or less, where X is the number of Faeries you control.

Cavern Harpy

Flying
When Cavern Harpy enters the battlefield, return a blue or black creature you control to its owner's hand.
Pay 1 life: Return Cavern Harpy to its owner's hand.

Moon-Circuit Hacker

Ninjutsu {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Moon-Circuit Hacker deals combat damage to a player, you may draw a card. If you do, discard a card unless Moon-Circuit Hacker entered the battlefield this turn.

Thorn of the Black Rose

Deathtouch
When Thorn of the Black Rose enters the battlefield, you become the monarch.