If you only mulligan away Astounding Revelation (in a standard 33 card deck) and nothing else: Chance you open with no copies: 96.9% With 1 copy: 3.1% With 2 or 3 copies: 0% This is because if you happen to get no copies in that opening hand, you mulligan nothing, staying at 0
It's still a lasting reason for players to be concerned when facing off against a known Superfriends deck as the Big Bad, but against other decks it's probably a scheme that can be ignored unless a very strong one exists in the Archenemy's deck
Since only one spell per turn is castable, counters are nasty, and thus an uncounterable draw win con here is powerful there and your dorks tend to be nasty size so you can go really big, really quickly
FAQ 1) How long can I expect to get the sample
Note, that while technically more expensive, buying the four pack of boosters is still more cost effective as you ultimately save on delivery, and that would probably be my recommendation for anyone looking to pick up a few packs without any stress