The Great Mending(or just the Mending) was a process that healed Dominaria from the damage caused by the time rifts through the sacrifice of multiple planeswalkers.
Pauper: Peregrine Drake will be banned in Pauper
Standard: Attune with Aether is banned. Rogue Refiner is banned. Rampaging Ferocidon is banned. Ramunap Ruins is banned.
Modern: Jace, the Mind Sculptor is unbanned. Bloodbraid Elf is unbanned.
Legacy: Deathrite Shaman and Gitaxian Probe are banned
Standard: Standard Rotation Kaladesh
Modern: Krark-Clan Ironworks is banned.
Pauper: Gush, Gitaxian Probe, and Daze are banned.
Modern: Bridge from Below is banned.
Standard: Rampaging Ferocidon is unbanned.
Modern: Hogaak, Arisen Necropolis banned. Faithless Looting is banned. Stoneforge Mystic is unbanned.
Standard: Throne of Eldraine Rotation
Standard: Field of the Dead is banned.
Pauper: Arcum's Astrolabe is banned.
Standard: Oko, Thief of Crowns is banned. Once Upon a Time is banned. Veil of Summer is banned.
Legacy: Wrenn and Six is banned.
Currently doing updates, some information might not be entirely accurate. Check again in a few minutes.