The Saviour of Summerset achievement is found in your Journal under Achievements - Summerset - General
To unlock this you must complete:
- The Good of the Many - The main quest started by talking to Razum Dar outside Shimerene.
- Relics of Summerset - Find the 20 relics stolen from the vault of Moawita - Locations here
- Summerset Grand Adventurer - Complete any 33 unique quests in Summerset
- Defender of Summerset - Defeat the six group bosses in summerset - Doing the daily quests for Justiciar Farowel at Rinmawen's Plaza in Alinor will send you to each of these locations.
- Summerset Master Explorer - Complete Summerset Pathfinder (discover all striking locales) and Summerset Cave Delver (clear all 6 explorable caves)
- Karnwasten Group Event - Defeat the Sea Sload K'Garza in Karnwasten
- Sunhold Group Event - Interrupt the executioners and defeat the Leviathan in Sunhold
Thanks to
The Unofficial Elder Scrolls Pages for additional information.