Lens flare ftw!
(that one was for you, vrt)
I'm not quite sure if this would see much play, given the existence of Quintessence and the nature of
rush decks. They are typically few creatures with very low hp, so this card would not only take away another card in a 30-card deck, but also would more often than not be played after your threats because of quantum constraints in an Immolation deck. Also, because of the existence of Nova and Immolation, Cloak would be easier to cast and wouldn't interfere with the
quanta needed to cast creatures.
My two