Evoke is an alternative casting cost found on creatures. Casting a creature for its evoke cost is often cheaper than paying its normal mana cost, but it causes that creature to be sacrificed after it enters the battlefield.
The creature's other enter-the-battlefield abilities still happen, which is what makes evoke so useful. Ephemerate can even blink an evoked creature before its sacrifice trigger resolves, returning it to the battlefield permanently. Creatures such as Solitude and Subtlety provide powerful interaction immediately upon entering.
