Arcana: Utility Modifiers
Arcana provide spell modifiers—Options like Unstoppable, Vulnerable, or Diablo 4 Items Healing, among others. They are unlocked by:

Seasons' Codex Chapters – Daily and weekly objectives.

Helltide Encounters – Chests at event completion.

World Events Whisper Trees – Whisper rewards often include Arcana.

Nightmare Dungeons – High-challenge zones have rarer Arcana.

Arcana have three rarities—Magic (base), Rare, Legendary—with differing power.

4.4 Horadric Jewels: Passive Gear Enhancements
Horadric Jewels go into socket slots on gear for passive benefits—boosting your Catalysts or class abilities. They’re acquired by:

Nightmare Dungeons – High reward zones.

Seasonal Bosses / Giants – Dropping Jewels at victory.

Codex Milestones – Lone Jewels infused into goals.

Seasonal Events – Challenge rewards, sometimes hidden or rare.

Jewels also tier in rarity: Normal, Rare, Legendary. Some adapt to Arcana themes, scaling bonuses based on the number of Arcana equipped for a specific school (Control, Power, Denial, etc.).

Section 5: Crafting Your Power — From Blueprint to Ability
5.1 Step-by-Step to Building a Spell
Open the Spellcrafting Interface.

Choose an available Catalyst.

Assign an Infusion—the spell now deals elemental damage.

Apply an Arcana to add unique utility or effects.

Preview the description.

Craft to consume the materials.

Assign it to your action bar, replacing or augmenting a slot.

You can create and equip up to several Horadric Spells—as long as diablo 4 duriel mats you have space and component availability.