The July 13 update to Magic: The Gathering's Banned & Restricted list is one of the biggest we've seen as of late. Four different formats had changes implemented, and nine cards ultimately had their status changed. Read on to see what got the Obsidian Battle-Axe, and what got the Second Chance.
The Historic format saw the most changes with this update. Three cards that were previously suspended (Agent of Treachery; Winota, Joiner of Forces; and Fires of Invention) have now been outright banned from the format. WotC reported that the suspension of these cards saw an improvement in the meta, and decided to keep them out of the competitive game. Additionally, Nexus of Fate has been banned from the format, as too many of the top decks are relying on a combination of that card and Wilderness Reclamation; the latter is not being restricted, as it has only proven to be an issue when paired with Nexus of Fate. Finally, Burning-Tree Emissary has been suspended, in order to try and blunt the dominance of Gruul Aggro decks, which are becoming more and more prevalent in top-level play.
The Pioneer format has a card being unbanned: Oath of Nissa. The card was banned early in the format to try and weaken the dominance of green ramp decks, but a number of other green ramp cards have been banned since then, including the infamous Oko, Thief of Crowns. As a result, WotC feels that Oath of Nissa can return to the battlefield.
One card is being banned from the Modern format for being too powerful: Arcum's Astrolabe. This card is currently making it too easy to play very powerful multi-color cards, as the Astrolabe comes at a low cost and doesn't force the user to compromise their mana spread. Such decks have a 55% win rate for non-mirror matches, and as such, WotC made the decision to ban the card.
Finally, the Pauper format will see two cards banned. Tron decks have become very popular in the format, and they unfortunately are leading to more restrictive play, with recursive patterns and lots of repetitive gameplay. As a result, Expedition Map is being banned, to try and weaken Tron decks somewhat. Additionally, Mystic Sanctuary has been banned from the format, as it makes loops and lock states too easy to achieve.
At the moment, there have been no changes to Standard. WotC has noted the popularity of Growth Spiral, but they are taking a wait-and-see approach as the metagame evolves in response to the release of Core Set 2021.
The full list of banned and restricted cards can be found here.