Season 9: Sins of the Horadrim introduces Spellcrafting, a new system that lets you create and customize a skill using a mix of effects. By combining different elements, you can build spells that add entirely new effects to your build or your core skills.
How Spellcrafting Works
You will find the Horadric Spellcrafting Interface in your character screen, right where seasonal powers used to go. From there, you can slot in:
- 1 Catalyst: the base spell
- 1 Infusion: changes the elemental type of damage
- 3 Arcana: modifiers that add unique effects
You activate your Horadric spell through your regular Action Bar skills. Your skill icon will glow purple when the spell is ready to go.
Be careful where you place the Catalyst in the interface, as it has to match your Skill Bar. The spell will trigger when the linked skill to this position is used. If you decide to switch your skills around on your action bar, make sure to also remember to move your catalyst appropriately.
Where to Get Spell Elements
- Catalysts and Infusions are earned through the seasonal questline.
- Arcana can be found by exploring Nightmare Dungeons.
Catalysts
Catalysts are the starting point of your spell. They determine its shape, cooldown, and core function.
- Each Catalyst has its own cooldown, Lucky Hit chance, and a special Rank 10 bonus.
- You can place your Catalyst on a specific slot in your Action Bar. It will activate when you use this specific skill, if ready.
- Catalysts can be improved by using Infusions and Arcana.
| Catalyst | Cooldown | Lucky Hit Chance | Power | Rank 10 Power |
|---|---|---|---|---|
 Celestial Surge (Astral Magic) | 15 seconds (11.2 at Rank 20) | 18% | Awaken an Oracular Rune that Pulls In all surrounding enemies. A torrent of stars follow that randomly strike the area 20 times for damage each. | Stars periodically fall around you and are guaranteed to crash around a Nearby enemy for the same damage. |
 Disintegrate (Arcane Magic) | 10 seconds (5.3 at Rank 20) | 9% | Form an Arcane Conductor that emits a persistent beam between itself and you, dealing a steady blitz of damage over 8 seconds. | Enemies within the beam are Slowed by 50%. |
 Propulsion (Arcane Magic) | 8 seconds (3 at Rank 20) | 15% | Generate a Mana Blast that delivers damage and Knocks Back all foes. Enemies that collide take another damage. | The Knock Back is gargantuan and enemies slammed into terrain by it form a Lesser Mana Blast the first time it happens to them. |
 Cosmic Anomaly (Astral Magic) | Spawn Rate: Every 5 seconds | 20% | Passive: Manifest up to 5 Anomalies that emit particles which deal damage over 4 seconds. Active: Command your Anomalies to converge and implode, dealing damage per detonation. | While at 5 Anomalies, you are Unstoppable and the next implosion will deal double damage. |
 Astral Pillar (Astral Magic) | 7 seconds | 12% | Shape an Ethereal Column that Taunts for 3.0 seconds. Piercing waves flow from it and deal damage, until you create another one or move too far away. | The Taunted enemies become Vulnerable and move faster. |
Infusions
Infusions let you change the type of elemental damage or damage-over-time of your Catalyst. They are important when finding the right setup for your build.
At Rank 5, each Infusion unlocks a bonus that lets your spell disable certain monster affixes (like suppressor or lightning-resistant).
| Infusion | Damage Type | Bonus Power | Rank 5 Power |
|---|---|---|---|
 Smoldering Ember | Fire, Burning | It destroys enemy structures and has a 10% chance to ignite the ground beneath enemies, dealing 450% Burning damage over 5 seconds. While equipped, your Fire Damage Bonus is equal to that of your highest Damage Type Bonus. | Deactivates monster Chilling Winds effects for 8 seconds. |
 Nebulous Extract | Shadow, Corrupting | Enemies hit by it deal 5-10% reduced damage for 7 seconds. While equipped, your Shadow Damage Bonus is equal to that of your highest Damage Type Bonus. | Deactivates monster Summoner effects for 8 seconds. |
 Glacial Nimbus | Cold, Frostbiting | Enemies damaged by it are Chilled for 15-25%. This effect happens once per enemy every 1 second. While equipped, your Cold Damage Bonus is equal to that of your highest Damage Type Bonus. | Deactivates monster Explosive effects for 5 seconds. |
 Corrosive Vapor | Poison, Poisoning | Enemies damaged by it take 320% Poisoning damage over 4 seconds. This effect can only happen on each enemy every 3 seconds. While equipped, your Poison Damage Bonus is equal to that of your highest Damage Type Bonus. | Deactivates monster Vampiric effects for 8 seconds. |
 Thunderous Particle | Lightning, Sparking | Enemies damaged by it arc 320% Lightning damage to a surrounding enemy. This effect can only happen on each enemy every 3 seconds. While equipped, your Lightning Damage Bonus is equal to that of your highest Damage Type Bonus. | Deactivates monster Suppressor effects for 8 seconds. |
Arcana
Arcana are spell modifiers. You can stack up to 3 to fine-tune how your Catalyst behaves.
- Arcana come in Magic, Rare, and Legendary rarities.
- Legendary Arcana adapt their effect based on which Catalyst they are linked to.
- Many Arcana carry spell tags that interact with other effects, including Horadric Jewels.
| Arcana | Rarity | Power |
|---|---|---|
 Tendrilous Bundle | Magic | Lucky Hit: Damage from your Catalyst has up to a 35% chance to Immobilize for 5 seconds (+5% each rank). |
 Tranquil Stone | Magic | Invoking your Catalyst grants Unstoppable for 3 seconds whenever it activates (+0.4 each rank). |
 Shifting Powder | Magic | Your Catalyst increases your Movement Speed by 30% during its effect and for 5 more seconds after it ends (+8% each rank). |
 Luminous Gem | Magic | Your Catalyst will Daze enemies it damages for 2 seconds (+1 each rank). |
 Murky Essence | Magic | Invoking your Catalyst grants Stealth for 2 seconds whenever it activates (+0.4 each rank). |
 Invigorating Helix | Magic | Once per enemy every 5 seconds, damage from your Catalyst will Fortify and Heal you for 5% of your Maximum Life (+1% each rank). |
 Bottled Wind | Magic | Invoking your Catalyst grants a Barrier equal to 30% of your Maximum Life for 4 seconds. After it dissipates, its essence is bottled back up (+4% each rank). |
 Jagged Bramble | Magic | Lucky Hit: Damage from your Catalyst has up to a 50% chance to deal 150% of your Thorns damage (+30% each rank). |
 Reactive Ooze | Magic | After your Catalyst activates, you gain 5% Maximum Resource Generation per second for the next 10 seconds (+3% each rank). |
 Volatile Crystal | Magic | After your Catalyst activates, it grants 10% Resistance and Maximum Resistance to the Element of your Infusion for 10 seconds (+2% each rank). |
 Gleaming Conduit | Rare | The effect size of your Catalyst is increased by 10% (+8% each rank). |
 Fractured Core | Rare | Your Catalyst deactivates monster Damage Resistance Aura effects for 2.5 seconds, but you take 10% more stacking damage for the same time (+0.5 each rank). |
 Sapping Crux | Rare | Your Catalyst applies Vulnerable for 3 seconds (+1 each rank). |
 Potent Alloy | Rare | Your Catalyst destroys enemy Barriers and Knocks them Down for 1.0 seconds after the removal (+0.8 each rank). |
 Siphoning Gizmo | Rare | Lucky Hit: Damage from your Catalyst has up to a 50% chance to deal 200% Physical Damage. Your Catalyst Lucky Hit Chance is doubled. (+30% each rank). |
 Floaty Bobble | Legendary | Your Catalyst gains a specialized blink effect that grants Unhindered for 2.0 seconds. (+0.4 each rank). Floaty Bobble creates the following effects for each Catalyst: – Celestial Surge: Blinks you to the center of its Oracular Rune when it forms and grants Unhindered. – Disintegrate: Blinks you to your target but leaves its Arcane Conductor behind. You are Unhindered while the beam is active and for 2.0 seconds afterwards. – Propulsion: Blinks you to the center of the blast and makes you Unhindered for 2.0 seconds. The melee variant blinks you to the Knocked Back enemies. – Astral Pillar: Blinks you to your focused destination and grants Unhindered for 2.0 seconds while dropping the flare at your previous spot for ranged variants. – Cosmic Anomaly: Blinks you to its implosion, grants Unhindered, and cleanses all your negative effects. |
 Nightmare Orb | Legendary | Your Catalyst gains a specialized Fear effect that lasts 4.0 seconds. (+0.4 each rank). Nightmare Orb creates the following effects for each Catalyst: – Celestial Surge: Stars Fear unaffected enemies and deals 100% increased damage to them while they are Feared. – Disintegrate: Fears unaffected enemies for 4.0 seconds. Killing affected enemies restores 5% Maximum Life and Primary Resource. – Propulsion: Removes enemy Vulnerable effects to Fear them. While Feared, those enemies randomly form Lesser Mana Blasts. – Astral Pillar: Every 9th wave Fears Enemies close to it are Taunted and have their Fear removed. – Cosmic Anomaly: Anomalies Fear and apply an 90% Slow to unaffected enemies they come into contact with. |
 Frigid Heart | Legendary | Your Catalyst gains a specialized Freeze effect that lasts 3.0 seconds. (+0.4 each rank). Frigid Heart creates the following effects for each Catalyst: – Celestial Surge: The Oracular Rune from Celestial Surge explodes and Freezes enemies. A second one forms after the star strikes end. – Disintegrate: Your Disintegrate beams Freeze all affected enemies for 3.0 seconds after you Evade and also grant 15% Dodge Chance for double that duration. – Propulsion: Enemies that collide twice are Frozen for 3.0 seconds. – Astral Pillar: The flare Freezes surrounding enemies for 3.0 seconds when removed. Each Freeze increases your Lucky Hit Chance by 10% for 5 seconds, up to 25%. – Cosmic Anomaly: Anomalies have a 30% chance to preserve themselves instead of imploding and Freeze surrounding enemies. |
 Pressurized Steam | Legendary | Your Catalyst gains a specialized Stun effect that lasts 1.0 seconds (+0.4 each rank). Pressurized Steam creates the following effects for each Catalyst: – Celestial Surge: The stars have a 25% chance to Stun and are guaranteed to Critically Strike Stunned enemies. – Disintegrate: After being invoked, Disintegrate Stuns each enemy it damages one time. This Stun applies 100% more Stagger to Bosses. – Propulsion: Enemies slammed into terrain by Propulsion are Stunned and have a chance to miss their next 2 attacks. – Astral Pillar: Waves have a 30% chance to Stun for 1.0 seconds and are guaranteed to Overpower Stunned enemies. – Cosmic Anomaly: The particles from your Anomalies deal their damage instantly and have a 25% chance to Stun. |
 Bloody Charm | Legendary | Your Catalyst gains a specialized Execute effect for non-Boss enemies with 10% or less Life. (+2% each rank). Bloody Charm creates the following effects for each Catalyst: – Celestial Surge: The moon’s impact Executes non-Boss enemies with 10% or less Life. Successful Executions reduce your Cooldowns by 2 seconds. – Disintegrate: Non-Boss enemies with 10% or less Life are immediately Executed. This threshold is doubled for non-Elite enemies. – Propulsion: The Mana Blast from Propulsion will Execute non-Boss enemies. Successful Executions grant 70% Movement Speed for 5 seconds. – Astral Pillar: Will launch additional waves towards Executable non-Boss enemies to Execute them. – Cosmic Anomaly: Executes non-Boss enemies with its implosion. Successful Executions increase your Attack Speed by 20% for 8 seconds. |
Upgrading Spells
To empower your spells, you can use Horadric Phials, a seasonal currency, to upgrade your elements. You can earn the seasonal currency by playing seasonal content, such as Nightmare Dungeons, and defeating Lair Bosses.
- Open the Horadric Spells menu (press C on PC) and get to the seasonal tab to upgrade your Catalyst, Infusion, or Arcana.
- Hover over an element and press F on PC to upgrade it.
- Each upgrade boosts your spell’s power and can unlock rank bonuses.
- Costs go up as you level higher.
Make sure to upgrade and scale your Horadric Spell as you level up to match your character’s strength.
Your Horadric spell does not replace your core skill; it is only triggered with a specific skill. Make sure to choose spells that fit your playstyle. And most importantly: Do not overlook Arcana tags, as some of the best synergies come from stacking the right effects across gear and spells, and keep upgrading your elements as you push into endgame content.
