Aaron can choose
Breaking // Entering as a card with CMC 3 or less, because it has a CMC of 2.
Aaron can also choose
Breaking // Entering as a card with CMC 4 or greater, because it also has a CMC of 6.
Distended Mindbender doesn't say that the cards you choose have to be different, so Aaron may choose Breaking // Entering twice during the resolution of
Distended Mindbender's ability, causing only that card to be discarded.
The ruling you quoted is not intended to imply that the two choices must be different cards, merely that if you are able to make legal choices for the ability, you must do so even if you don't like your only available choices. (For example, if you start to resolve the Mindbender's ability and find that the only cards in your opponent's hand are
Loxodon Smiter and
Wilt-Leaf Liege, your opponent will be getting two free creatures whether you like it or not.)
Edited Callum Milne (Sept. 28, 2016 04:53:19 AM)