From Press Release:
This season is all about the loot and features sweeping changes to itemization. Try out the new Tempering and Masterworking systems to upgrade your gear and craft the perfect build for your playstyle. Then, take your new gear into the updated Helltide to challenge new events and enemies. You need not face this threat alone, though! The Iron Wolves are ready to stand by your side in the brand-new seasonal questline. Whether you look forward to creating a new seasonal character or love going back to your eternal character, these itemization and Helltide updates are available in both the Season and Eternal Realm, so jump into Sanctuary today!
For more details on what’s in Season 4, check out: https://news.blizzard.com/en-
For everything Diablo IV, you can check out the official website.
