With Magic: The Gathering Core Set 2020 spoilers underway, Chandra was introduced via three different rarity planeswalker cards, but all other planeswalkers in the set will be Mythic Rare cards.
Wizards of the Coast rolled out the red carpet (pun intended) for Core Set 2020 with three different Chandra planeswalker cards, each having a different rarity assigned to them. Chandra, however, is the exception as the rest of the set will only contain Mythic Rare planeswalkers.
Most sets contain a mix of Rare and Mythic Rare planeswalkers but War of the Spark broke that rule in having Uncommon, Rare, and Mythic Rare. In order to not overflood Standard with more planeswalkers, Core Set 2020 will limit itself to Mythic Rare planeswalkers only, with Chandra and her three cards being the exception.
For Mono-Red Aggro, Grixis Control, and Rakdos players—the three Chandra planeswalkers are more than enough. Containing enough power to break holes in all the Esper archetypes, M20 is already changing the Standard metagame.
Not having any other Rare planeswalkers in M20, other than Chandra, could spell trouble for the other archetypes. Mono-Red Aggro is already the most played deck in Standard and it just got a whole lot stronger. Perhaps Magic: The Gathering will make up the difference by increasing the number of Rare legendary creatures in other colors, instead.
The release date for Magic: The Gathering Core Set 2020 is July 12.