DevoidDevoid is a characteristic-defining ability. “Devoid” means “This object is colorless.” This ability functions everywhere, even outside the game. See rule 604.3. (CR 702.114) (This card has no color.)
Return target nonland permanent you don't control to its owner's hand.
Whenever you
castTo cast a spell is to take it from the zone it’s in (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. A player may cast a spell if they have priority. See rule 601, “Casting Spells.”
To cast a card is to cast it as a spell. (CR 701.5) a colorless spell with mana value 7 or greater, you may
exileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) this card from your graveyard. When you do, return each nonland permanent you don't control to its owner's hand.