The Pandemonium Event is a Battle.net only event in Diablo 2. Introduced in Patch 1.11 of the Diablo II: Lord of Destruction, the Pandemonium Event it is the most challenging adventure players can get into while playing the game.
There are a lot of special Bosses throughout the Pandemonium Event, and completing it is a lot more complex than most of the other battle.net exclusive content.
Here, you will have a short guide that allows you to access the Pandemonium Event.
Obtaining the Keys
The Minor Keys need to be found in order to open the minor portals that will allow you to obtain the major keys. There are three different minor keys to be found, and to open any one of the minor portals, you need to have a complete set of three different keys. This means, that the player will have to collect, a total of nine keys (three of each type).
To obtain the Minor Keys, you have to defeat the three agents of the Prime Evils in Hell difficulty.
They have a chance to drop their key along their normal drop, but the chances to do so are quite rare. The player will have to do about 10 to 15 runs per Boss in order to obtain the key they drop.
Once you have a complete set of three different Minor Keys, head to Harrogath in Act V. Put all three Minor Keys in the Horadric Cube and transmute them. Doing so, will create a portal where you will fight a more powerful Boss.
- Uber Duriel can be found in the Forgotten Sands. Drops Baal's Eye.
- Uber Izual can be found in the Furnace of Pain. Drops Mephisto's Brain.
- Lilith can be found in the Matron's Den. Drops Diablo's Horn.
When you have all three items, you can create a new portal, this time, leading to Uber Tristram.
Note that it is recommended that you collect all 9 required Minor Keys and open all three portals within the same game. Choosing to do this in separate games, may lead to the same portal opening in two different games, completely wasting a set of three Minor Keys.
Reaching Uber Tristram
Once you have all three Major Keys, head back to Harrogath and use the Horadric Cube to transmute them. This will create a portal to Uber Tristram. Uber Tristram has exactly the same structure that Tristram does when you visit it during The Search for Cain.
This time more powerful Demons lurk Tristram, but the main objective during your visit is to find and defeat Uber Mephisto, Uber Baal and Pandemonium Diablo. Once you manage to defeat the three Prime Evils, the one that falls last will drop two Unique items. The Standard of Heroes, a commemorative item that serves as a proof that the player has completed the Pandemonium Event; and an unidentified Hellfire Torch, an incredibly powerful Large Charm.