You get a 12/12 trampling monster, plus a powerful and flexible ability that triggers whenever you attack, so you dont have to wait until Ghalta and Mavren itself attacks to get the benefit
Incapsula incident ID: 329000760010003295-32774921227145999
Nearly half of Battle for Zendikar has been spoiled at the time of writing and one thing is clear: Wizards of the Coast wants us to play with expensive and awesome Eldrazi creatures the same way we did during the era of Rise of the Eldrazi
The non-Secret Lair version will always be different from what the Secret Lair offered, but might keep the same name, representing the same character/object/place aka it wont always be a Universe Within version. Theres not going to be a single way to do this
You can only use this effect of "Blackwing - Chinook the Snow Blast" once per turn.
You can only Special Summon Phantasmal Sacred Beasts of Chaos once per turn this way, no matter which method you use