Wizards of the Coast has already banned 13 cards from the MTG Arena Historic format and one card from Brawl before the release of Modern Horizons 3.
6 Cards Banned! | Magic: The Gathering 3/9 Banned and Restricted Announcement
The Modern Horizons 3 set is full of powerful cards that are meant to impact formats like Commander and Modern. These cards are also coming to MTG Arena, playable in the Limited Draft and Sealed, Historic, Timeless, and Brawl formats. In order to keep the digital Historic format healthy, WotC already banned the Evoke Elementals and Flare cycle from MH3 on June 3, along with Harbinger of the Seas and Winter Moon.
Here are all of the pre-banned MTG Arena cards for the MH3 historical format, according to WotC.
"We've been cautious about cards that can be cast for free with alternate payments, as we feel they're too fast for this format," WotC said. "So it shouldn't come as a surprise that we're banning the Evoke Elementals and Flare cycle for Modern Horizons 3, but they will be playable in Timeless."
