Neverwinter

Preface

The "Master of Fragments" is for completing two special expeditions in Stardock. You gain access to Stardock after completing the Undermountain adventure. If you completed the Undermountain adventure and do not have access to Stardock, head to the top floor of the Yawning Portal through the curtain and complete the expedition (accessed from the map on the table).

Note: Undermountain was previously a campaign and your previous progress, if you had any, was converted towards this adventure.

Gaining Access to the Mission

Once in Stardock, you will gain access to two different reconnaissance missions a day. One mission for Githyanki reconnaissance and one mission for Illithid reconnaissance. After completing the two reconnaissance missions for a faction, you will receive a new quest for a Warden Expedition. Each warden mission gives a piece of a faction's rod.

Once you have 3 pieces of a faction's rod, you can do the factions' Fragment expedition.
Note: You will need to complete two of these Fragment expeditions per faction (4 in total) for the achievement.

Gathering Runic Corruption to Make Runes

You will find runic controlled areas in Undermountain. You kill enemies in these events to get resonance which then can be converted into runes. You can convert this resonance into runes at the altars inside of the Fragment expeditions.

https://imgur.com/jRuetNQ
Here is an example of a runic controlled location. It's yellow so you would get yellow crystalized resonance which can then be converted into a yellow rune. There are five different types (colors) of runic corruption.

This is a picture of the crystalized resonance. It appears in your "Riches" tab of the inventory under "Other Currencies".
https://imgur.com/q6xSNDG

You will need 10 resonance of a specific color to make a rune. In total you will need a minimum of 60 crystalized resonance to make the 6 runes needed. They can all be of the same color if you choose.

Completing the Missions

Once you gathered all the crystalized resonance, start one of the fragment missions. In the starting area, you will have three pillars to attune runes. Here you can convert your resonance into runes and attune them to the expedition. These will make the expedition harder, but the content is old and un-scaled so it shouldn't be too hard for 50-60k item level characters.

Be sure to attune three runes before leaving the expedition starting area. Only the party leader can attune runes. You can pass the lead to another person and have them attune runes as well.

Once you get to the end you will fight one of the special bosses (Red Dragon Knight or Neothelid) depending on which fragment mission you selected.

Rinse and repeat for the other fragment mission. Congratulations, achievement unlocked!