You can create pretty consistent scenarios where you play a room card and unlock the other door: Victor, Valgavoth's Seneschal lets you surveil 2 while your opponents discard a card
Cam Shea has worked at IGN since the before times, and has played more Breath of the Wild than just about any other game
Double-faced cards also return, and side quests will be one of the things adding unique flavor to the set
Amass The return of the amass mechanic from War of the Spark is a massive shock
Any creature with variable casting cost and power is worth trying, but Stonecoil is probably the most flexible and most powerful option we have
You can achieve a similar effect with a free sacrifice outlet, Mikaeus, the Unhallowed, and a persist creature like Putrid Goblin