Diablo 4 Season 9: Sins of the Horadrim — Everything You Need to Know

Season 8 of Diablo 4 is still underway, but details about Season 9 have already been revealed! With each new season, Diablo 4 continues to evolve, bringing fresh content, unique mechanics, and changes that breathe new life into the familiar gameplay. Season 9 will launch under the name Sins of the Horadrim, and what awaits us is sure to please longtime Diablo 4 fans. We’re in for a major update featuring a brand-new seasonal mechanic, exclusive items, reworked dungeons, and an entire questline that dives deeper into the lore of Sanctuary. In this blog, I’ll try to cover everything I’ve learned about the upcoming season in as much detail as possible.

Season 9 Release Date and Time

According to the in-game timer, Season 9 will begin on Tuesday, July 1, 2025, at 10:00 AM PST. The new season will launch immediately after the end of the Return of Belial event, so if you haven’t had the chance to explore all the content from the previous season, now’s the time to catch up.

The test servers for the new season will be open to everyone starting Tuesday, May 27, 2025, at 10:00 AM PST and will run for exactly one week — until Tuesday, June 3. During this period, you’ll be able to try out the core features of Season 9, provide feedback, and help the developers polish the final version of the update. So if you’re a true fan and want to contribute to improving your favorite game, I wish you a productive test run and a great time in Sanctuary.

Key Features of Season 9

With Season 9, Diablo 4 continues to expand its seasonal systems, introducing fresh content and new ways to enhance your character. Below are the core features that will shape the gameplay experience in the coming months:

• New Seasonal Power Mechanic: Horadric Spells
• New Seasonal Items: Horadric Jewels
• New Seasonal Event: Nightmare Dungeon Escalation
• New Micro-Dungeons: Horadric Strongrooms
• Nightmare Affix Updates
• New Seasonal Storyline and Questline
• Season Journey and Season Blessings
• Reliquary Battle Pass System
• New Seasonal Reputation System
• New Unique Items
• Keyboard and Mouse Support on Consoles

Season 9 looks like a solid update with a clear focus on deeper mechanics and replayability. There’s plenty to dive into — whether you’re chasing progression or simply want to experiment with new builds. It’s also worth noting that this season will further expand the game’s lore, so if you enjoy immersing yourself in Sanctuary’s story, you’ll find plenty to explore as well.

Horadric Spells

Season 9 introduces a reworked character enhancement system — Horadric Spells. Previously known as Horadric Powers, this system now offers greater depth and flexibility. Similar in concept to seasonal powers from past updates (like those tied to bosses or witches), it now revolves around a combination of three components: Catalysts, Infusions, and Arcana.

• Catalysts are the core of the spell, activating when you use a specific skill on your action bar. Each one grants a unique effect, and upon reaching level 10, gains an additional bonus. There are five in total — ranging from starbursts to surges of energy.
• Infusions enhance your Catalysts with elemental damage, from toxic vapor to icy storms or electric surges. Upon reaching level 5, Infusions can also suppress enemy affixes, offering more tactical flexibility during combat.
• Arcana are supplementary modifiers applied to Catalysts that shape your playstyle. They come in three tiers of rarity: Magic, Rare, and Legendary. The higher the rarity, the more powerful and unique the effect. Legendary Arcana, for example, adapt based on the active Catalyst and can greatly amplify your build’s potential.

All Horadric Spell customization options are housed in a dedicated tab on the character screen — located to the left of your inventory. This is where you can monitor your spell progression and fine-tune combinations to match your playstyle.

Overall, Horadric Spells feel like an ambitious evolution of the “borrowed power” systems seen in past seasons. If implemented well, this could become one of the most memorable features Diablo 4 has introduced to date.

Horadric Jewels and Strongrooms

Season 9 of Diablo 4 brings back a mechanic previously seen in Season 7 — Horadric Jewels. These items enhance your character by increasing armor, elemental resistance, and core stats. However, not all of them are purely beneficial: some Jewels come with negative effects as well, so make sure to choose wisely when slotting them into your build.

Complementing this system are Horadric Strongrooms — new micro-dungeons that appear randomly while running Nightmare Dungeons. These locations are reminiscent of Rootholds and Hellbreaches from previous seasons. Inside, you’ll face waves of enemies and earn a special currency called Horadric Attunement, which is granted for each kill. The more Attunement you collect, the better the rewards from the final boss of the Strongroom. Additionally, interacting with optional Trials during the run allows you to boost your Attunement even further and increases your chances of obtaining rare loot.

Escalating Nightmares

Escalating Nightmares are a brand-new endgame activity introduced in Season 9. In this mode, players must complete three Nightmare Dungeons back-to-back — with each subsequent dungeon inheriting the affixes from the previous ones. This stacking effect significantly increases both the difficulty and the quality of rewards.

To begin an Escalation, you’ll need a special item called the Escalating Nightmare Sigil, which can be found in Horadric Strongrooms starting at Torment I difficulty and higher.

At the end of the third dungeon, you’ll face Astaroth Reignited, a reimagined version of a familiar boss. While Astaroth won’t be featured as a Ladder Boss this season, there’s a possibility he may be added to the Lair Boss rotation in future updates.

New Unique and Legendary Items

Each class will receive one brand-new Unique item in Season 9, designed to expand build variety and unlock new playstyle possibilities. Alongside these additions, players can also expect new Legendary Aspects to be introduced, offering fresh synergies and tactical options.

In addition to the new gear, the season will bring a round of balance changes to existing items and aspects — aimed at refining class performance and keeping the meta dynamic.

Reliquary Battle Pass

Season 9 introduces a new Reliquary system within the Battle Pass, featuring personalized reward tracks. Players will be able to unlock a variety of cosmetics and gear — including mounts, pets, armor sets, weapons, and more.

A new system featuring personalized reward tracks, including mounts, pets, armor, weapons, and more.

Season Transition

At the start of Season 9, all characters from Season 8 will be automatically transferred to the Eternal Realm. To experience the new mechanics and content, you’ll need to create a new character — as is standard in Diablo 4’s seasonal mode.

All items from the previous season will be moved to the Withdraw Only tab in your Eternal Realm stash. However, keep in mind that you’ll have a limited time to retrieve them. Anything left unclaimed by the end of Season 9 will be permanently lost.