Once they have arrived in Mount

Once they have arrived in Mount Zavain at one of D2R Items the times mentioned above and players will be able to see it is clear that the Ancient Nightmare has arrived, and they are able to use D2R Ladder's auto-navigation feature to navigate to it. 

For those who are present when you see Ancient Nightmare appear should receive an email notification. Clicking on "OK" will immediately put an individual in motion towards the boss. You can also look at the Ancient Nightmare in the Misty Valley If they're having difficulties finding it using auto navigation.

After finding after locating the Ancient Nightmare, D2R Ladder players have to follow the boss, waiting that it will pass through any of the Altars within the area. Once that happens, players must engage with the Altar and feed a Zakarum Sword into it. This causes a dome of luminescence to emerge from the Altar and temporarily remove the Ancient Nightmare's shield and let players deal damage to the boss.

For a quick overview, Zakarum Sigils are made available by Lord Martanos the boss in D2R Ladder that appears in Mount Zavain. Additionally, players are able to create Martanos in the Martanos Altar which is located found in the crypt 

that is located at the northwest part of the Zakarum Graveyard, and it is possible to fight Martanos every 30 minutes. Although it's definitely not necessary that players possess sufficient Sigils to cover the entirety of buy D2R Ladder Items the Ancient Nightmare event by themselves However, it could be useful to have a few on hands prior to engaging in a fight with the boss.