How to Use Catalysts in Season 9: Customize Powerful Horadric Spells

Season 9: Sins of the Horadrim opens a fresh chapter in Diablo’s evolving combat system with the introduction of Horadric Spellcraft—a new way to build powerful spells using Catalysts, Infusions, and Arcana. Whether you’re new to spellcrafting or a seasoned explorer of Sanctuary’s arcane arts, understanding how to wield Catalysts is the first step toward unlocking the full potential of this system.

What Are Catalysts?

Catalysts serve as the core of every Horadric Spell you create. Think of them as the spell’s backbone—providing its fundamental behavior, damage type, cooldown, and trigger condition. Catalysts define the spell's function, while Infusions and Arcana modify and enhance it.

Each Catalyst has:

• A specific cooldown that determines how often it can be triggered
• A Lucky Hit Chance, which offers a probability to trigger additional effects
• A Rank 10 Bonus, giving it a powerful boost when leveled
• A connection to your Action Bar Skill, which glows purple when the Catalyst is ready

How to Use Catalysts Effectively

To use Catalysts:

1. Equip a Catalyst in the Horadric Spell interface (accessible via Wayfinder or Mrak on the PTR).
2. Link it to one of your Action Bar Skills—that skill will become the activator for your Catalyst spell.
3. When your Catalyst is off cooldown, your Action Bar Skill will glow with purple energy.
4. Press the skill to unleash your Catalyst’s core spell effect.

After equipping a Catalyst, you can further customize it by adding:

• 1 Infusion – to change elemental damage (e.g., Fire, Ice, Lightning)
• 3 Arcana – to enhance the Catalyst’s behavior (like increasing range, adding debuffs, or boosting crits)

Featured Catalysts in Season 9

Let’s look at some of the highlight Catalysts available in Sins of the Horadrim:

Celestial Surge (Astral Magic)

• Effect: Pulls in all enemies and bombards the area with 20 falling stars.
• Cooldown: 15s (11.2s at Rank 20)
• Lucky Hit: 30%
• Rank 10 Bonus: Stars passively fall around you and target nearby enemies.

Playstyle Tip: Great for AoE burst and crowd control—ideal in dungeon chokepoints.

Disintegrate (Arcane Magic)

• Effect: Creates a beam of arcane energy between you and a conduit, dealing continuous damage.
• Cooldown: 10s (5.3s at Rank 20)
• Lucky Hit: 9%
• Rank 10 Bonus: Slows enemies inside the beam by 50%.

Playstyle Tip: Combine with slowing or stunning Arcana for battlefield control.

Propulsion (Arcane Magic)

• Effect: Blasts enemies with mana, knocking them back. Collisions cause more damage.
• Cooldown: 9s (4.3s at Rank 20)
• Lucky Hit: 15%
• Rank 10 Bonus: Massive knockback with terrain slams causing a secondary mana explosion.

Playstyle Tip: Perfect for pushing elites into environmental hazards.

Cosmic Anomaly (Astral Magic)

• Passive: Spawns Anomalies that deal damage over time.
• Active: Implode the Anomalies for burst damage.
• Spawn Rate: Every 5s
• Lucky Hit: 20%
• Rank 10 Bonus: At 5 Anomalies, gain Unstoppable and double implosion damage.

Playstyle Tip: Time your activation for boss phases or crowd nukes.

Astral Pillar (Astral Magic)

• Effect: Summons a Taunting pillar that deals pulsing damage.
• Cooldown: 7s
• Lucky Hit: 12%
• Rank 10 Bonus: Taunted enemies become Vulnerable and speed up.

Playstyle Tip: Use in tank builds or to redirect aggro away from squishy allies.

Where to Find Catalysts

During PTR testing, you can access Catalysts and other spell components via Mrak the Vendor.

At Season launch, obtain them by:

• Catalysts & Infusions: Progressing through the Seasonal Questline
• Arcana: Exploring and clearing Nightmare Dungeons

With the Horadric Spell system, Season 9 hands you a magical sandbox. Catalysts give you the blueprint for your spell, but the real magic lies in experimentation. Mix different Catalysts with creative Arcana and elemental Infusions to tailor a spell that matches your playstyle—whether that’s melting mobs with Disintegrate or turning the battlefield into a starry trap with Celestial Surge.