The Infernal Machine is a device that once crafted opens a portal to another realm where you can face off against Uber versions of Diablo 3 bosses. It is also a required step in crafting the Hellfire Ring. Click any topic to jump to that part of the guide.

Getting parts for the Infernal Machine

• Key of Destruction - Fields of Misery, Act 1
• Key of Hate - Dahlgur Oasis, Act II
• Key of Terror - Stonefort, Act III
• Infernal Machine Plan - Silver Spire Level 1, Act IV

Realm of Uber Bosses

• The Entrance
• Uber Ghom & Rakanoth - The Realm of Chaos
• Uber Siegebreaker & Zoltun Kulle - The Realm of Turmoil
• Uber Skeleton King & Maghda - The Realm of Discord

Hellfire Ring

• Crafting the Hellfire Ring & Ring Stats

Extra Information

• Video of Uber Ghom & Rakanoth
• Video Guide to location of the Keywardens

Before we begin here is some general information about the Keywardens.

• You need 5 stacks of Nephalem Valor for a key to drop.
• Every Monster Power level increases the chance for keys to drop, at Monster Power level 10 they have 100% chance to drop. (As long as you have 5 stacks)
• The Keywardens are a guaranteed spawn in each game but may spawn anywhere on the specific maps.
• You can have more than 1 key at a time.
• A new machine must be built each time you want to fight another pair of bosses.

Falcon Punch!

Key of Destruction - Odeg the Keywarden

The first Keywarden is found anywhere in the Fields of Misery of Act I. Odeg has the Molten and Jailer affixes and a fire attack that shoots three balls of fire. His regular attack is a ranged spear throw. Just remember that when Odeg dies he will leave behind a exploding ball of fire that can kill you!

Let's be friends

Key of Hate - Sokahr the Keywarden

The second Keywarden is found anywhere in the Dahlgur Oasis of Act II. Sokahr is a very anti-ranged monster as he has Missile Dampening, Mortar and Electrified as base abilities. His non-special attack is a spin attack that does damage to all those near him.

Which one is the real you?

Key of Terror - Xah'Rith the Keywarden

The third Keywarden is found anywhere in the Stonefort of Act III. He has the ability to teleport and periodically rain down corpses that explode causing a fair amount of damage while also creating a small area of ice that slows you substantially.

Ouch

Infernal Machine Plan - Nekarat the Keywarden

The last Keywarden drops the Infernal Machine Plan. He is found anywhere in the Silver Spire Level 1 of Act IV. Jailer, Knockback and Nightmarish are his main affixes along with a curse that reduces healing effects by 75%. Nekarat also has the ability to create a large firey spell on the ground that deals damage to anyone inside of it.

All I can think of is the Kool-Aid Man

Entrance to the Infernal Machine

Once you have all the materials you need to visit the blacksmith to create your Infernal Machine. After that it's time to enter the Realm of Chaos. The entrance can only be found on the last quest of Act I, "Return to New Tristram". Simply make your way to the healer in New Tristram and attack the door behind him. Once inside all you need to do is right click the Infernal Machine item in your inventory.

Uber Ghom & Rakanoth - The Realm of Chaos

In my opinion this is the easiest of all the Uber bosses. There is no changes to these bosses that I noticed and it's basically just fighting both Ghom and Rakanoth at once. In all my runs I killed Ghom first as I found it to be quite annoying having the entire room fill up with his poison clouds. This fight is easy enough where anyone with decent gear should not have any trouble.

Uber Siegebreaker & Zoltun Kulle - The Realm of Turmoil

This match up is a little bit harder than Ghom & Rakanoth due to the fact Zoltun Kulle has a lot of abilities that interfere with the fight. Getting caught in his slow time bubbles while Siegebreaker chases you down only to be hit by a Meteor from Zoltun Kulle is not fun. I decided to get rid of Zoltun Kulle first as his abilities have the biggest impact on the fight. I just had to make sure to dodge Siegebreakers charge and the fight was simple once Zoltun Kulle died.

Uber Skeleton King & Maghda - The Realm of Discord

This was the hardest fight for me and it is the only fight that changes the actual mechanics of the bosses. You have no choice but to kill the Skeleton King first because when Maghda hits 75% hp she will put a invincibility shield on herself until every single monster including the Skeleton King is dead. If that wasn't bad enough you have to deal with constant Arcane Enchanted beams everywhere, as the Skeleton King keeps raising Skeletons and Maghda shoots her bug cloud at you. Have fun!

Crafting the Hellfire Ring & Ring Stats

Quick facts about the ring:

• Crafting cost - Vengeful Eye, Devil's Fang, Writhing Spine and 50,000 Gold.
• Writhing Spine is acquired by defeating Uber King Leoric and Maghda.
• Vengeful Eye is acquired by defeating Uber Siegebreaker and Zoltun Kulle.
• Devil's Fang is acquired by defeating Uber Ghom and Rakanoth.
• The plan is bought for 2 million gold from Squirt the Peddler in Act II.
• All the items required to craft the ring drop from the Uber Bosses.
• You need 5 stacks of Nephalem Valor for the organs to drop.
• Each Monster Power level increases the chance for each item to drop, at Monster Power level 10 they have 100% chance to drop. (As long as you have 5 stacks)
• You can choose either Dexterity, Strength, Vitality or Intelligence for the rings main stat. (Click the photo below to see full stats)
• The rings Hellfire Blast does 25,000 damage in a small area of effect.

Video of Uber Ghom & Rakanoth

Video Guide to location of the Keywardens