Sockets, Runes, and Support Setup

Weapon: Insert Iron Runes for spell damage scaling.
Armor/Jewelry: Use Elemental or Defensive runes to Path of Exile 2 Currency enhance resistances and survivability.
Socket Links: Maintain 3-4 linked sockets as soon as possible for multi-support setups.

Act 1 Core Setup

Contagion + Unleash - Fast multi-target spreading.
Essence Drain + Chain - Primary DoT combo for clearing.
Unearth + Prolonged Duration - Extends contagion effects.
Chaos Bolt + Rapid Casting - Wither stacking on bosses.

Act 2+ Bossing Setup

Despair (Cursed Ground) - Amplifies Chaos damage.
Dark Effigy + Controlled Destruction - Boosts DoT damage in tough fights.
Sigil of Power - Mana sustain and increased damage uptime.
Convalescence + Rapid Casting II - Defensive cooldown during bursts.

For early levels (2-5), Flame Wall provides an excellent temporary single-target supplement until Essence Drain becomes available.

Passive Tree and Ascendancy

Prioritize Eldritch Empowerment for base Chaos damage scaling, followed by Soulless Form for mana sustain. Once you've secured at least three Chaos damage clusters, respec early Intelligence nodes for a cleaner, optimized tree.

Recommended Permanent Buffs

Valley of the Titans Medallion: +30% Charm Charges.
Venom Crypts Poison Vial: +30% Ailment Threshold.
Orbala's Pillar: +3% Movement Speed.
Goddess of Justice: +30% Flask Mana Recovery.

Gameplay Flow

Clearing

Open with Contagion, follow with Unearth to summon scorpions that spread the infection, then apply Essence Drain for chain reactions across enemy packs.

Single Target

Activate Sigil of Power and Dark Effigy, apply Despair, then alternate Essence Drain and poe2 trade Chaos Bolt to maintain full Wither stacks. Refresh DoTs before expiration for maximum uptime.