Mill 30

Set:	Cheat Debug cards are cards designed for testing and debugging Hearthstone. Designed for use in a specific testing environment, these cards often featureSpecial attraction outlandish powers, and are not available to players. For technical reasons the cards
Type:	Spell Fireball, a simple mage spell. It costs 4 mana, dealing 6 damage to a chosen target. Spell cards are cards that can be played to trigger a one time effect or ability, described in the
Rarity:	Common Rarity is a rough measure of the quality and scarcity of a card. Cards of higher rarity are typically more powerful and more useful, but are harder to find and more expensive to craft. There

Put 30 cards from a hero`s deck into his graveyard.

See this card on Hearthpwn