Diablo 3 Walkthrough: Act 4, the High Heavens to Diablo

Part 4 of our Diablo 3 walkthrough covers Act 4, set in the High Heavens. It starts at the Diamond Gates after Diablo's invasion of heaven and ends on the Crystal Arch with the fight against Diablo himself. It is a short act with four quests and four bosses.

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The whole walkthrough

Quests in Act 4

1. Fall of the High Heavens
2. The Light of Hope
3. Beneath the Spire
4. Prime Evil

1. Fall of the High Heavens: Iskatu

You arrive at the Diamond Gates of the High Heavens. Demons are everywhere and Tyrael meets you there.

1. Talk to Tyrael. Your first job is to deal with the demon Iskatu and his minions.
2. Fight through to Iskatu. The real problem is the swarms of Shadow Vermin around him, not the boss.

Boss: Iskatu. A terror demon with low health and weak attacks. He can vanish and reappear. Clear the vermin with area skills, then focus him down. This is the easiest boss of the act.

2. The Light of Hope: Rakanoth

The archangel of Hope, Auriel, has been captured.

1. Find and talk to Itherael, the archangel of Fate.
2. Go into the Gardens of Hope. At the crossroads, the Library of Fate is to the west.
3. Kill Rakanoth in the Library, then destroy Auriel's prison and talk to her.
4. Back in the Gardens, destroy the Corrupt Growths to reveal hidden Hell Rift portals, and clear them. The quest log tells you which tier of the Gardens each one is on.
5. Take the portal Auriel opens near Tyrael to the Crystal Colonnade.

Boss: Rakanoth, Lord of Despair. He teleports around the room and his volley can briefly stop you in place. He summons Soul Lashers: kill them, because they always drop health globes. Stay mobile and save your escape skill for when he teleports on top of you.

3. Beneath the Spire

1. Find Imperius, the archangel of Valor, at the Crystal Colonnade. He is not happy to see you.
2. Enter the Gateway to the Silver Spire and fight through the Silver Spire levels.
3. Follow the quest marker up through the spire. The quest ends as you close in on the top of the Silver Spire.

There is no named boss in this quest, but the demon packs here hit hard. Take your time and use doorways to split packs.

4. Prime Evil: Izual and Diablo

1. Cross The Great Span of the Silver Spire. Izual blocks the way.
2. After Izual, climb to the Pinnacle of Heaven and the Crystal Arch.
3. Kill Diablo. Your follower can't help you in this fight.
4. Talk to Auriel at the Crystal Arch to finish the quest.

Boss: Izual. A fallen angel with ice powers.

• He swings a weapon in melee and has a slower, heavy slam.
• He makes ice crystals that freeze the area around them. Don't fight next to them.
• His Frozen Nova is hard to avoid without a movement or escape skill. Keep one ready.
• Kill his minions quickly, and use any slow or stun you have on Izual.

Boss: Diablo, Lord of Terror. The base-game final boss has three phases and no enrage timer, so you can take it slow. There are two health wells on the sides of the arena for phase 1 and phase 3.

• Phase 1: Diablo mixes fire, lightning breath and melee. His big trick is the Bone Prison: a bone cage that locks you in place. In a group, free each other. Solo, break out fast and expect damage. Keep moving so his breath and fire don't stack on you.
• Phase 2: partway through the fight he drags you into the Realm of Terror. Here you fight the Shadow of Diablo, who uses the same moves. Shadow clones of your own hero also appear. They use your class's skills, but each one drops a health globe when it dies, so kill them.
• Phase 3: you return to the arch. Diablo comes back with part of his health restored and gets more aggressive, with more teleports and new attacks. The health wells work again, so use them.

When Diablo falls, the base game story ends. Reaper of Souls continues in Act 5, Westmarch.

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Love the world? The Book of Tyrael covers the angels, demons and heroes of Diablo III.

Tips for this part

• Bring an escape skill. Izual's nova and Diablo's Bone Prison both punish heroes with no way out.
• Use the health wells smartly. Don't waste them at 80% life. Save them for after a Bone Prison or a bad breath hit.
• You are alone against Diablo. If your build leans on your follower for damage or crowd control, plan for that.
• Lower the difficulty if you need to. No one sees it, and you can raise it again in Act 5.

My take

Act 4 is short, and I think that works. It feels like one long push to the top of heaven. The Diablo fight is fine, but the Realm of Terror is the part I always remember. Did Diablo give you trouble, or was Izual the real wall for you?

FAQ

How long is Act 4 of Diablo 3?

Act 4 is the shortest act, with only four quests. Most players finish it in a single session.

What level do I need to beat Diablo?

There is no fixed level, since monsters scale to you. If Diablo is too hard, lower the difficulty or improve your toughness and healing before the fight.

Can my follower help against Diablo?

No. Followers can't join the final fight with Diablo. Plan your build to work on its own.

Is Diablo the final boss of Diablo 3?

He is the final boss of the original game. With Reaper of Souls, the story continues into Act 5, which ends with Malthael.

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