MTG Eldrazi Deck by Mattmatic

Destroy each artifact with mana value X or less.

If a land is tapped for two or more mana, it produces {C} instead of any other type and amount. Each spell a player casts costs {1} more to cast for each other spell that player has cast this turn.

Flash As this artifact enters, choose a card name. Spells with the chosen name cost {3} more to cast. Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Permanent cards in graveyards can't enter the battlefield. Players can't cast noncreature spells from graveyards or exile.

Devoid (This card has no color.) Kozilek's Return deals 2 damage to each creature. Whenever you cast an Eldrazi creature spell with mana value 7 or greater, you may exile this card from your graveyard. If you do, this card deals 5 damage to each creature.

As long as this artifact is untapped, each spell that would cost less than three mana to cast costs three mana to cast. (Additional mana in the cost may be paid with any color of mana or colorless mana. For example, a spell that would cost {1}{B} to cast costs {2}{B} to cast instead.)

This land enters tapped. When this land enters, exile target player's graveyard. {T}: Add {B}.

If this card is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand. {T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.