Diablo 4 Season 9 has finally arrived, and with it comes a host of fresh mechanics, new progression systems, and tons of exciting grind opportunities. Among the standout seasonal additions are the Horadric Strong Rooms, Arcana, Horadric Jewels, Opticsite, and Nightmare Dungeon Escalation events. If you've found yourself scratching your head about where to get Arcana or how to get more Horadric Vials, you're not alone.

This guide will walk you through everything you need to know to master Season 9 in Diablo 4 — including where Arcana comes from, how to optimize Horadric Strong Room farming, where to find your Vials, how to make your Horadric Jewels, and why you've probably missed tons of loot without even realizing it.

What Is Arcana and Where to Get It?

Let's start with the most commonly asked question: Where do you get Arcana in Season 9?

Many players mistakenly think Arcana drops are bugged, especially since they seem so inconsistent and often go unnoticed. But the truth is far more annoying: Arcana does not auto-pick up. That's right, even if you walk over it, unless you click on it, it just sits there waiting to be ignored and forgotten.

Where It Drops:

· Horadric Strong Rooms – These are the primary source.

· Nightmare Dungeon Escalation Bosses – These bosses can drop Arcana alongside Vials and even escalation sigils.

· Loot Cache (Horadric Cache) after killing a strong room boss.

Arcana comes in different item rarities and colors — blue, yellow, and legendary-colored drops — and they look almost identical to junk rares. If you're used to ignoring yellow gear on the ground, you've probably skipped right past valuable Arcana many times.

What Are Horadric Strong Rooms?

Strong Rooms are new events found within Nightmare Dungeons. When you see purple energy swirling around your character in a dungeon, that means you're close to a Horadric Gateway. Follow the glow to activate the gateway and enter the Strong Room.

Inside, you'll be able to interact with ritual pillars that change how your Strong Room encounter plays out. These modifiers can dramatically affect your gameplay, from summoning extra enemies to tethering mobs, or adding powerful demons for more loot.

Why You Want to Hit Attunement Rank 6:

The Strong Room progression system uses a mechanic called Attunement, which goes from 1 to 6.

· Rank 6 = Best rewards.

· Rank 1–5 = Still good, just less loot or lower chance of high-tier drops.

You don't need to reach Rank 6 to earn Arcana or Horadric Jewels — but the better your attunement rank, the better your odds. If you reach Rank 6 before the timer runs out, you'll immediately spawn the final boss and skip the remaining dungeon time.

Where to Get Horadric Vials

Horadric Vials are used to craft Horadric Jewels at the Lapidary crafting station. You'll need 3,000 vials per jewel, so farming them efficiently is crucial.

Top Vial Sources:

1. Nightmare Dungeon Escalation

   · After completing three Nightmare Dungeons, you'll fight Astaroth in the fourth dungeon.

   · Astaroth can drop 3,000–4,000 Vials and Horadric Jewels (the real thing — not recipes).

2. Horadric Strong Rooms

   · Vials are found in chests throughout the Strong Room, especially if you reach higher attunement ranks.

3. Specialized Dungeon Sigils:

   · Use specific Nightmare Dungeon sigils for better vial drop rates:

     · Gem Reserve – Mixed gem drops.

     · Amethyst Reserve – Tons of amethysts.

     · Corrupted Grotto – Very strong chest density and vials.

     · Gold Reserve / Equipment Delve – Great if you're low on Diablo 4 gold or gear.

4. Converting at the Lapidary:

   · Once you have enough Jewels or don't need more vials, you can convert leftover vials into reputation points.

Crafting Horadric Jewels

To craft a Horadric Jewel:

1. Go to the Horadric Lapidary, which unlocks via the main seasonal questline.

2. Select the jewel you want.

3. Spend:

   · 3,000 Horadric Vials

   · Gem Fragments

These Jewels provide powerful bonuses and are key to building strong endgame characters in Season 9.

How Reputation Works

If you've been farming layer bosses or opening their chests thinking you're increasing reputation, think again.

Real Reputation Sources:

· Killing Elites in Helltides

· Infernal Hordes

· Horadric Strong Rooms

· The Pit

The fastest reputation gains come from slaying elite mobs, not from chest farming or solo dungeon running. Keep an eye on elite spawns during Helltides or farm Strong Rooms in bulk.

Also, you can trade in extra Horadric Vials for Knowledge (reputation points) at the Lapidary. Great for late-season grind efficiency.

Seasonal Blessings Strategy

With Arcana, Vials, and Jewels in play, it's easy to overlook Seasonal Blessings — but these passives matter a lot.

Best Blessings to Focus On:

· Urn of Glyphs – More glyph upgrades.

· Urn of Curiosities – Purveyor of Curiosities gives double loot (amazing for Obols).

· Urn of Strong Rooms – Boost the drop rate of escalation sigils and extra loot from Strong Rooms.

· Urn of Knowledge (if late-game) – Convert Vials to reputation faster.

TIP: You can respect these blessings freely. If you're about to spend Obols, consider swapping to Curiosities and running Strong Rooms? Boost escalation sigils. Plan ahead!

Infernal Hordes – Do We Still Need Them?

Short answer: Yes, but not as much as before. The main reason to run Infernal Hordes in Season 9 is for Temper Reset Scrolls, which allow you to re-roll bad temper stats on gear.

Optimal Strategy:

· Do 6-wave runs only, enough to open the 200 Offering Chest.

· Get 2–3 Temper Reset Scrolls.

· Save Opticsite for other things — like Masterworking and glyph upgrades.

Opticsite Farming – Strong Rooms Are King

Opticsite is essential this season for crafting and Masterworking gear. The fastest way to gather it?

· Nightmare Dungeons (Torment 1 and above) always drop it.

· Horadric Strong Rooms drop tons more due to high enemy density and achievement chests.

In one dungeon run, players have reported gaining 8x Masterworked Diablo IV items and over 10,000 Opticsite without needing Infernal Hordes at all. Keep pumping through Strong Rooms, and you'll be swimming in Opticsite — just make sure you're playing on the right difficulty level (Torment or higher) for ancestral legendary drops.

Closing Thoughts

Diablo 4 Season 9 has a lot of layered systems that may feel overwhelming at first. But once you learn how Arcana, Strong Rooms, Vials, and Jewels connect — and once you stop accidentally ignoring that yellow glowing "junk" on the ground — the game opens up into a satisfying and rewarding endgame loop.

Whether you're pushing Nightmare Dungeons, crafting the perfect gear loadout, or simply enjoying the chaos of Strong Rooms, this season is packed with progression and payoff. So don't let Arcana slip through your fingers, and don't forget to open that Horadric Cache after the boss.