What is the amusing part? Having Proties face the wrath of God for not believing a legend? How about Peter? What about Paul, what king of wrath will he dish out on the Proties/those that question the Assumption?
The only amusing part of Pius’ XII Munificentissimus Deus is the arrogance displayed.
But Protestants believe a legend (amongst others) - the one about sola scriptura. It is amusing that some run around accusing others of belief in legends while they hold sola scriptura as doctrine.