[Update #2]: MTG Arena's viking themed expansion Kaldheim is launching on January 28, 2021.
[Update]: Two weeks after the previous ban, MTG Arena has now thrown out the dreaded Omnath.
If you're interested in giving MTG Arena a try, or simply looking to come back after a bit of an absence, this might be a pretty good time to do so. Not only has there been a set rotation that has seen four sets (Guilds of Ravnica, Ravnica Allegiance, War of the Spark and Core Set 2020) move from Standard to Historic, but a brand new expansion has just launched with nearly 300 new cards to mess around with!
The focus of the Zendikar Rising expansion is on five core mechanics, some universal and some belonging to specific color combinations. These would be the age-old effects like Mill (enemy discards cards from their library), Kicker (pay extra for extra benefits) and Landfall (effects trigger whenever your land enters the battlefield), as well as new mechanics like Party that require you to have a very D&D-like group of warriors, clerics, rogues and wizards in order to unlock special bonuses.
However, the fifth addition is by far the most interesting as they are double-faced cards that offer a land on one side, and a powerful but expensive spell on the other. Needless to say, this gives your late-game draws an additional bit of power since instead of drawing a boring ol' swamp, you can have a swamp or a spell that brings your creatures back from the dead! How powerful this will be in actual gameplay, that still remains to be seen since these lands come at a bit of a hefty price, but it's certainly an interesting mechanic to experiment with.
You can check out just what exactly these new modal double-faced cards (MDFCs) have to offer, as well as what the rest of the set is about, over at the official card list. Needless to say, there's quite a few cards to go through, so you might want to grab a cup of coffee beforehand.
Have fun, and I'll leave you with the fair lengthy cinematic trailer that helps set up the new Zendikar storyline: