Saviors of Uldum — Hearthstone's new expansion — will be available on August 6. Check our dedicated article containing all cards that have already been unveiled, or find below all details related to this new Epic Mage Spell: Puzzle Box of Yogg-Saron!
Honestly, it's quite hard not to see in this spell some kind of troll or joke from Blizzard. Obviously, when you hear "Yogg-Saron" within a card name, you know that its effect will revolve on RNG. That's why Puzzle Box of Yogg-Saron is almost unplayable: because it is too much random to be viable.
Come on, the simple fact that you might cast 10 Pyroblasts to your own face should be enough to make you consider twice when adding Puzzle Box of Yogg-Saron to your deck. The probability is thin... but it's still there. Plus, we did not count all scenarii where the spells you would have cast would have been terribly bad.
At least, you will cast your 10 spells — which is still better than a Yogg-Saron targeting itself with a Shadow Word: Death. Still, it's our right to wonder about the competitive interest of this spell. It might be a way to weaken the Cyclone Mage, as getting Puzzle Box of Yogg-Saron will definitely be a disappointment.
Overall, we need to wait until all cards are released, because some weird overpowered interactions might rise in the next few weeks.