For each opponent,
exileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) up to one target permanent that player controls with an even mana value. (Zero is even.)
AdamantAn ability word has no rules meaning of its own. It groups abilities with similar themes; the text following it explains this card’s effect. (CR 207.2c) — If at least three colorless mana was spent to
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) this spell, return a permanent card with an odd mana value from your graveyard to the battlefield.