There will be an Arena Open: Foundations event on the weekend of November 30th.
There will also be “…a popular event returning on November 22nd…” with no further details given.
It’s possible this will be an Arena Direct event, although that is pure speculation at this point.
Every other event talked about in this announcement, and some that aren’t, can be found on my Event Calendar.
Starting when Foundations goes live on November 12th, there will be 10 new decks added to everyone’s account. These are “preview versions” of what the new player decks will be and will contain over 400 cards from both the main Foundations set as well as from the Starter Collection, including 50 Rare and Mythic Rare cards.
As a reminder, neither the Beginner Box nor the Starter Collection will be available to buy on Arena, so this is likely the best available option to get such a massive influx of cards to people without breaking everyone’s Wildcard bank.
Monstrous Rage has been banned in Alchemy.
Temporal Manipulation has been banned in Historic.
There are also a number of rebalances to Alchemy cards, including Leyline of Resonance, Heartfire Hero, Grenzo, Nadu, and more. Please see the Source article above for full details.
There are no further details about Arena Champoinship 7 at this time, however an article from March was recently updated to include a December 14th & 15th date for this event. The formats and structure are still unkown at this time.
