Break Open

Morph created a hidden-information layer the rest of the rules engine was never built to interrogate, and this is an earnest, doomed answer to it. The pitch is simple: a face-down attacker is a question, and for two mana you can force the answer. The problem is who that answer belongs to. Flipping an opponent's face-down creature does not pay its morph cost; it just turns the card over, which means you have spent your own resources to do, for free, the very thing the controller would otherwise have had to pay for. Worse, any "when this is turned face up" trigger fires on their behalf, gifting them the unmorph payoff a turn early and at no cost. The creature you most want to expose (an expensive morph the controller could not yet afford to flip, one with a punishing turn-face-up trigger) is precisely the one this rewards them for owning. The only clean line is against a true bluff, where the hidden creature was nothing worth respecting and you have now confirmed it at the cost of an instant and a card from your own hand, a confirmation that rarely earns its price. It is a tidy demonstration of how hard it is to attack hidden information without handing your opponent the information, and the resources, you were trying to deny them.