We'll Take Astaroth Diablo 4's Season 9 finally lets us fight Astaroth in the endgame, but the rest of what it brings feels like a re-skin of old systems Diablo 4's Season 9 may not be the one that saves the game, but at least it's bringing back that Astaroth boss fight. Image credit: Blizzard Entertainment. News by Sherif Saed Contributing Editor Published on May 23, 2025 Right on schedule, Blizzard delivered a long and detailed livestream covering Diablo 4’s upcoming patch 2.3.0 PTR (Public Test Realm). The developer revealed when the PTR will be going online, and what it’s actually going to include. The PTR will, as previously revealed, only be available on PC through Battlenet. It will go live next week, on Tuesday, May 27, ending one week later on June 3. To see this content please enable targeting cookies. As you may recall from the Diablo 4 roadmap, Season 9 is titled Sins of the Horadrim. The structure of the next season will be similar to recent ones: there’s going to be a new activity or two, with the new gameplay revolving mainly around powers you can acquire as you play said activities. For Sins of the Horadrim, the new endgame activity is called Escalating Nightmares (previously Dungeon Escalation), and the powers will be Horadric Spellcraft. Astaroth will also return as part of the season. The highlight of the new season is the ability to create Horadric Spells, a new system that relies on three elements to function: Catalysts, Infusions, and Arcana. Catalysts are the base, unmodified powers, which you can then alter with Infusions. This changes the elemental damage type of the spell, but you can also change the baseline power of it using Arcana. The system, in essence, is a refresh of Season 7's Witchcraft Powers, and is similar to Season 8's Boss Powers in the way it works, too. Look familiar? | Image credit: Blizzard Entertainment. Something else being introduced with Sins of the Horadrim is Horadric Strongrooms. These are micro-dungeons that can be found within larger Nightmare Dungeons. Your goal is to claim some lost Horadric knowledge within, and fight your way out in time, as a timer kicks in after you trigger a Strongroom. Doing so will earn you Horadric Attunement, which can later be exchanged for rewards. The chances of Horadric Strongrooms spawning increase the higher your Torment level, but you can also use Horadric Phials (a new seasonal currency) to increase your chance of finding them further. Some Nightmare Dungeon Sigils will also guarantee a Horadric Strongroom can be found within. Horadric Strongrooms follow a similar dungeon design where you get to choose what sort of challenge you want to take on by interacting with one of the different Horadric Pillars. Once the ritual is performed and the pillar is satiated, you’ll get Horadric Attunement. At the end of it, there’s a boss you’ll need to fight to complete the run. Before you leave, you’ll get to use your Horadric Attunement to acquire a Horadric cache. He's back! | Image credit: Blizzard Entertainment. The big new activity in Season 9 is Escalating Nightmares, which is a fancy name for a new chain of three Nightmare Dungeons, with nightmares escalating as you go through each. The main hook here is that each dungeon’s affixes stack with the next one, meaning the third in the chain will have affixes from all three. If you manage to go through all three, you’ll get to fight an Exalted version of Astaroth. Triggering an instance of Escalating Nightmare requires an Escalation Sigil, which can be found in Horadric caches from the aforementioned Strongrooms (starting from Torment 1). The Astaroth fight itself is one of the most impressive and memorable fights from Diablo 4’s campaign, and players have been asking Blizzard since launch to bring it into the endgame. This version has something of a mechanical twist, too. Astaroth will jump off his mount, essentially forcing you to fight both him and Amalgam. This isn’t just a visual trick, either, because slaying Amalgam before Astaroth sends the hound into a resurrection state that will put it back in the fight after some time. Watch on YouTube As you might have guessed, there’s a major focus on dungeons in Season 9. Blizzard is turning its gaze to dungeons across both the Seasonal, and Eternal Realms. This will encompass a few tweaks, as well as some new quality of life changes. You’ll soon be able to activate a Nightmare Sigil from within the Nightmare Dungeon itself once it’s complete, meaning you’ll be able to re-run the same one without having to leave and re-enter to create a new instance. The pool of Nightmare Dungeon affixes is also being bolstered with a set of new ones, available across both realms. Then there’s Horadric Jewels, which will be available in Torment 1 and beyond. Completing a Strongroom has a chance to spawn Horadric Tomes, which, when consumed, let you craft Horadric Jewels. These are effectively gems, just with some powerful effects that play nicely with your Horadric Spells. You’ll also need Horadric Phials and Gem Fragments to craft them, and they can only be socketed into Amulets and Rings. Catch up on the full change log on the Diablo 4 blog, which also includes PTR-specific boosts those taking part will need to rely on if they want to get into endgame content quickly.