Shortly after Pioneer was revealed as a format it was announced that as the new offering was taking shape, there would be an update every Monday with regards to the banned list. In an effort to craft the best possible format, Play Design is taking an aggressive stance early on in Pioneer’s life to try and target problem cards.
The first of these series of announcements came on November 4th. Felidar Guardian, Leyline of Abundance, and Oath of Nissa are all banned. Four-Color Copycat and Green Devotion Ramp had the most 5-0 finishes in Magic Online leagues and these bans are aimed to help with diversity moving forward.
Felidar Guardian got the axe due to its infinite combo with Saheeli Rai and because if one of those cards is more likely to break again, it would be the cat. Leyline of Abundance decks were early front runners in Pioneer due to their ability to generate a ton of mana early with cards like Elvish Mystic, Nissa, Who Shakes the World, and Nykthos, Shrine to Nyx. Oath of Nissa was banned to reduce the consistency of Planeswalker-based strategies.
These bans go into effect on November 5th in Magic Online and on November 8th in tabletop. The next Pioneer announcement, regardless of whether or not there are bans, will be on November 11th.