Firelands Portal and the Not-So-New Arena Metagame
If you're a staunch follower of Kripparian on YouTube, then you've heard the rant: Firelands Portal in Ranked Play is broken. It's a 7 to cast COMMON card that deals 5 damage AND summons a random 5-cost minion.
Like Kripp says, the most important tilting factor of the card isn't so much it's effects (because it's barely going to find use in Constructed, if any) but rather the Rarity.
COMMON cards mean that your chances of picking them in a draft like Arena are higher. Mage is ALREADY the class with the largest amount of removal in the common slot, with basic cards like Flamestrike and Fireball appearing very often. Adding another to this arsenal, not even counting the second part of the card, is already amazing in a format where card value is key and removal just does so much. Then you ALSO build your board with a minion (not even counting what value this minion might be - Don't even get me started).
Kripp is right, it skews the metagame further in the direction it's already skewed towards. But I look at the arena meta these days and it's still crawling with mages, like it always has, Sometimes momentarily knocked off the throne into 2nd, but usually never far behind.
Mage has just time and time again proven to be a resilient contender in the arena meta, and even if things have just shifted heavily in their favor, in many ways, it always has.
Mage has gotten a dash in the lead once again, but if you ask me, for the most part, things have still stayed the same: Mage is still the 'terror' in the Arena Play meta.