Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Kozilek's Unsealing

Devoid (This card has no color.)
Whenever you cast a creature spell with mana value 4, 5, or 6, create two 0/1 colorless Eldrazi Spawn creature tokens with "Sacrifice this token: Add {C}."
Whenever you cast a creature spell with mana value 7 or greater, draw three cards.

Myr Enforcer

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)