Diablo II: Resurrected Act IV, “The Harrowing,” is the shortest but most intense act in the game. Set in the Pandemonium Fortress floating above the gates of Hell, it serves as a direct bridge to the final confrontation with Diablo. Players usually enter around level 30–35 and finish near level 35–40. The act focuses on rescuing a fallen angel, forging a powerful artifact, and slaying the D2R Ladder Items Lord of Terror himself.

Arrival at the Pandemonium Fortress

After defeating Mephisto in Act III, a red portal transports you to the safety of the Pandemonium Fortress. Speak to all NPCs immediately: Tyrael (quest giver), Deckard Cain, Jamella (healer and merchant), and Halbu (mercenary captain). Activate the waypoint right away for easy town access.

Quest 1: The Fallen Angel

Tyrael tasks you with finding Izual, a corrupted angel. Leave the fortress through the north gate into the Plains of Despair. The area is filled with powerful demons, including Doom Knights, Venom Lords, and Oblivion Knights. Locate Izual (marked on the minimap once nearby) and defeat him. Speak to him after the fight to learn the location of Diablo, then return to Tyrael for a reward of two skill points — extremely valuable at this stage.

Quest 2: Hell’s Forge

This quest involves creating the Hellforge Hammer and destroying Mephisto’s Soulstone.

Find the Hellforge in the River of Flame area.

Defeat the Hephasto the Armorer (a super-unique monster who guards the forge). He drops the Hellforge Hammer.

Place Mephisto’s Soulstone (from Act III) and the Hammer into the Hellforge to destroy it in a spectacular cinematic.

Rewards include rare and unique gems, plus the satisfaction of permanently weakening the Prime Evils.
Final Quest: Terror’s End

Quest 3: Terror’s End (Tyrael)

Proceed through the City of the Damned and River of Flame to reach the Chaos Sanctuary. This large, circular area contains five seals. Opening each seal spawns waves of powerful monsters (including Oblivion Knights and Storm Casters). After all seals are broken, Diablo is released from his prison.

Boss Fight: Diablo

Diablo, Lord of Terror, is a formidable final boss for Act IV. He uses a devastating arsenal:

Red Lightning Hose (massive lightning damage)

Fire Wall and Apocalypse spells

Bone Prison and Cold Touch melee attacks

Summoned minions

Fight Strategy:

Stack high lightning and fire resistance (75%+ is recommended).

Use the pillars and corners for line-of-sight to break his lightning attack.

Bring plenty of Rejuvenation Potions and a strong mercenary (Desert Merc with Holy Freeze or an Act III Iron Wolf).

Focus on consistent damage while dodging his most dangerous abilities. Crushing Blow, Open Wounds, and cold damage help control the fight.

Once Diablo falls, Tyrael appears, congratulates you, and opens the portal to Act V in the frigid lands of Harrogath.

General Act IV Tips

Act IV is compact but extremely dangerous. Clear methodically and use Town Portal scrolls often.

The River of Flame is an excellent farming spot for runes and uniques.

Hire a strong mercenary from Halbu and keep them well-equipped.

Stockpile resistances, especially lightning and fire.

Resurrected’s improved particle effects and sound design make the hellish atmosphere more immersive than ever.

Act IV tests everything you’ve learned so far and prepares you for the mountain siege in Act V. With smart preparation and solid resistances, you’ll overcome the cheap D2R Ladder Items Lord of Terror and continue your journey to stop Baal. The endgame is now within reach!