Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

{T}: Add {U}. Channel — {3}{U}, Discard this card: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.