To be able to craft tier 3 armor sets you will have to unlock a special entrance to Naxxramas.
To be able to unlock the special entrance to Naxxramas you must first complete the steps in How to Unlock Old Scholomance.
I want to thank the amazing community on the Secret Finding Discord for their efforts in figuring out all of these secrets!
Step 1: Enter old Scholomance
You can enter the old Scholomance dungeon, by clicking on Eva's Enchanted Journal. Once opened, click on the option that reads "Read the grim history of Scholomance."
This journal can be found within the same keep where the newer Scholomance is located. As you enter the keep, avoid taking a left towards the newer dungeon.
Instead, make a right turn and continue down the hallway ahead of you. Keep going until you reach the ritual area where you previously placed Eva's Enchanted book.
Step 2: Finding the Argent Dawn Commission Trinket
Once you've entered the original version of Scholomance, your goal is to head down to the basement of the dungeon. When you get there, you'll notice a bunch of skeletons and piles of bones scattered all over the place.
Look out for the first pile on the left side of the room. In that pile's corner, you'll find the Cracked Argent Dawn Commission, a tiny object that's easy to miss.
Step 3: Obtaining the Darkmaster's Scourgestone
If you're still in the basement, defeat Rattlegore, who can be found in the middle of the area. Loot the Viewing Room key from him and head back up the stairs. Take a right through the gate and use the key to unlock the door. Proceed through the first left gate and make your way downstairs.
As you go down, you'll reach the boss's chamber. However, before the boss spawns, you need to defeat the mini-bosses in the area. You'll notice six doors—three on the upper level and three on the lower level where the boss will eventually appear. Clear out each room behind those doors.
Once the boss spawns, don't forget to equip the Argent Dawn Commission trinket before engaging the boss. With the trinket equipped, the boss will drop a Darkmaster's Scourgestone, which triggers the "Darkmaster's Scourgestone" quest.
/way Eastern Plaguelands 75.76, 53.81 Duke Nicholas Zvernhoff
To complete this quest, head over to Light's Hope Chapel and turn it in to Duke Nicholas Zvernhoff.
Once you turn in the quest he will grant you the ability to acquire Scourgestones in Stratholme, Scholomance, and Naxxramas while wearing the trinket.
After gaining the ability to acquire Scourgestones, you want to make your way to Stratholme in the Eastern Plaguelands.
Once you're inside the dungeon, you want to locate an Eye of Naxxramas. This NPC will randomly spawn as you kill mobs within the dungeon. However, it consistently spawned at the marked location after killing a few mobs. When the NPC spawns it will yell "The living are here!", so it should be pretty easy to spot. Once you defeat an Eye of Naxxramas, be sure to loot it and obtain the Ward of Naxxramas.
Using this ward will grant you a 2-minute buff called Truesight. However, before you use the ward and receive the buff, be sure to loot a Stratholme Holy Water from the Supply Crates scattered throughout the dungeon.
(Make sure to grab a few extra Stratholme Holy Water because you will need them later on in Naxxramas.)
Once you have looted the Holy Water and the Ward, make your way to the Crusader's Square inside the dungeon. In front of the gate, use the Ward of Naxxramas, and then use the Holy Water on the spawned ward.
As soon as you throw the Holy Water on the ward, you will gain the Sleight of Hand debuff, which lasts for 5 minutes. This debuff requires you to reach The Hand of Naxxramas within 5 minutes or less.
You need to kill Baroness Anastari, Nerub'enkan and Maleki the Pallid to open the gates to the Slaughter Square. When you defeat one of these bosses a door will open behind them. Make sure to walk through the door and defeat the Acolyte NPCs. It is not enough to just kill the bosses. If you only kill the bosses the gate to the Square will not be open.
Before you enter the Square make sure you defeat Magistrate Barthilas as well. So, all bosses should be defeated within the Gauntlet map before you can proceed the the Square and defeat Ramstein the Gorger and the final boss, Lord Aurius Rivendare.
After defeating the final boss, you need to make your way to the gate just outside where the boss is located. Walk up to the closed gate where The Hand of Naxxramas is standing. (number 8 on the map above)
As you approach the gate, an extra action button will appear called to dust, which you need to use. If you successfully completed all of this within the time limit, you will receive the following message in the chat:
"As the Hand of Naxxramas burns into a pile of ash, it is clear that recent events have escalated such that someone should be made aware of them."
The person mentioned in the message is Archmage Angela Dosantos, who can be found in Light's Hope Chapel.
Step 5: The Dread Citadel - Naxxramas Quest
Once you return to Light's Hope Chapel, your next step is to seek out Archmage Angela Dosantos. She can usually be found there, but in some cases, depending on your progression of the story in that zone, she might be located in Tyr's Hand.
Once you locate Angela, engage in conversation with her and choose the option:
"Frantically explain the recent events to Angela as if your life depended on it!"
After selecting this dialogue option, you will have the opportunity to accept a quest called "The Dread Citadel - Naxxramas," which requires you to turn in a certain amount of items depending on your standing with the Argent Dawn.
/way Eastern Plaguelands 75.48, 52.80 Archmage Angela Dosantos
If you have are Honored with the Argent Dawn, you can accept "The Dread Citadel - Naxxramas". In order to complete this quest, you will need to turn in the following items:
- 5x Arcane Crystal
- 6x Large Brilliant Shard
- Righteous Orb
- 60 Gold
If you have are Revered with the Argent Dawn, you can accept "TThe Dread Citadel - Naxxramas". In order to complete this quest, you will need to turn in the following items:
- 2x Arcane Crystal
- 3x Large Brilliant Shard
- 30 Gold
If you are Exalted with the Argent dawn you will be able to accept The Dread Citadel - Naxxramas, which requires no mats and is free.
Step 6: Entering the Portal to the Special Naxxramas
/way Eastern Plaguelands 35.72, 23.05 Revealed Portal To Naxxramas
After successfully completing the quest, you will be rewarded with the Wards of the Dread Citadel achievement.
This achievement grants you access to a special entryway that leads to Naxxramas. To enter this special version of Naxxramas, you can use a ward that is located in the Eastern Plaguelands.
Upon completing the quest, you will be rewarded with the Empower Commission, which grants you the ability to uncover ancient secrets and acquire corruptor's scourgestones within Naxxramas.
This benefit extends account-wide, allowing every single character to explore Naxxramas and collect scourgestones without having the Argent Dawn Commission trinket equipped.