Wizards of the Coast has revealed the new cycle of Magic: The Gathering modal double-faced (MDFC) cards in Zendikar Rising during the official livestream of the set reveal today. Check out the cycle of 6 MDFC land cards below:

There are three ally-colored rare lands and three enemy-colored rare lands. The cards include:
These cards will let you choose which side you want them to be when you play them, and they don't have a drawback, so I think they're great mana-fixers that will definitely see play in Standard and other formats.
You can check out how the new MDFC cards work in this video from WotC:
Wizards also revealed another MDFC card in their livestream.
Zendikar Rising is set to release on September 25, 2020; it will release on MTG Arena on Sept. 17.
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