Delve

MTG Mechanic

Spells with delve are very powerful, but usually have a high mana cost. Fortunately, you don't need to pay all of it with mana. The Sultai's ruthlessness leads them to use every resource at their disposal, even the dead. As you're paying for the spell, you can exile cards from your graveyard. Each card you exile this way pays for one generic mana.