These achievements are associated with the uprising Fractured. There are 310 legacy points spread between 17 achievements in 4 subsections and 1 unobtainable achievement. All of the achievements can be completed in 3 runs of the uprising, one in each difficulty.
10 Legacy Points
This achievement is unlocked for locating the Imperial Spy once in any difficulty. The spy is on a ledge above the platform where the T4-9K Excavator is encountered. To reach the spy you'll need to use the grapple point to jump across the chasm, then turn left to the ramps of the embedded doorway. At the top of the ramp is a small ledge on the left that you can follow to reach the spy. You just need to get within a few meters of the agent on the ledge for the achievement to trigger. The activities needed to complete this are;
[STORY] Uprising: Inferno | [VETERAN] Uprising: Inferno | [MASTER] Uprising: Inferno
10 Legacy Points
This achievement is unlocked for killing 1,000 enemy combatants in any difficulty. Although it requires a high number of deaths, this is easily completed in 3 runs, one on each difficult level. The enemies needed to complete this are;
Battle Droid | Construction Droid | Excavation Foreman | Excavation Security | Excavation Technician
Explosive Specialist | I4-K8 | Imperial Heavyweight | Imperial Medic | Imperial Siege Trooper
Imperial Skirmisher | Lord Adacin | Lord Wrad | Lord Zanisk | Sentry Droid | Sith Acolyte | Sith Adept
Sith Apprentice | Sith Enforcer | T4-9K Excavator
10 Legacy Points | 10 Legacy Points | 10 Legacy Points | 10 Legacy Points
These achievements are unlocked for defeating T4-9K Excavator, Lord Adacin and Lord Zanisk, Lord Wrad, and progressing through the staging area each once in [VETERAN] difficulty. The activity needed to complete these is;
[VETERAN] Uprising: Inferno
10 Legacy Points
This achievement is unlocked for completing uprising Inferno once in [VETERAN] difficulty. The enemies needed to complete this are;
Clear the Staging Area | Lord Adacin and Lord Zanisk | Lord Wrad | T4-9K Excavator
10 Legacy Points | 10 Legacy Points | 10 Legacy Points | 10 Legacy Points
These achievements are unlocked for defeating T4-9K Excavator, Lord Adacin and Lord Zanisk, Lord Wrad, and progressing through the staging area each once in [STORY] difficulty. The activity needed to complete these is;
[STORY] Uprising: Inferno
10 Legacy Points
This achievement is unlocked for completing uprising Inferno once in [STORY] difficulty. The enemies needed to complete this are;
Clear the Staging Area | Lord Adacin and Lord Zanisk | Lord Wrad | T4-9K Excavator
25 Legacy Points | 25 Legacy Points | 25 Legacy Points | 25 Legacy Points
These achievements are unlocked for defeating T4-9K Excavator, Lord Adacin and Lord Zanisk, Lord Wrad, and progressing through the staging area each once in [MASTER] difficulty. The activity needed to complete these is;
[MASTER] Uprising: Inferno
25 Legacy Points
This achievement is unlocked for completing uprising Inferno once in [MASTER] difficulty. The enemies needed to complete this are;
Clear the Staging Area | Lord Adacin and Lord Zanisk | Lord Wrad | T4-9K Excavator
100 Legacy Points
This achievement is unlocked for completing uprising Inferno once in [MASTER] difficulty without dying. It seems that the legacy points and achievement are not accessible at this time. The activity needed to complete this is;
[MASTER] Uprising: Inferno