You can unlock different types of Survivors. Craftspeople offer important quests and a variety of crafting workshops. Assistants are ideal for having your workshops available in multiple bases. Townsfolk make your base more lively and can also offer smaller quests.
The craftspeople with a workshop are on the NPC pages. Where their souls are and the quest that rescues each:
BalthazarAlchemistNear Ancient Vault - Alchemist, SpringlandsPowerful AlchemyLoraine CrimAncient ResearcherNear Cinder's Ascent, Cinder's CradleLand Of The Sky IslandsValoryBardNear Sunken Ancient City, BlackmireFollow The MelodyOswald AndersBlacksmithNear Ancient Vault - Blacksmith, SpringlandsFind the Sleeping SurvivorCade HawthornCarpenterNear Ancient Vault - Carpenter, SpringlandsCarpentry AssistanceAlden CrowleyCollectorExplore The Hollow HallsEmily FrayFarmerNear Ancient Vault - Farmer, RevelwoodGrowing Stronger TogetherCaptain Melville FontaneFisherNear Ol' Captain's Rest, Veilwater BasinEmerald Shores And Sanguine SeasAthalan SkreeHunterNear Ancient Vault - Hunter, SpringlandsHunter Becomes The HuntedMei-Yin ChenLunar New Year TraderNear Hidden Tomb Entry, SpringlandsRinging In The New Year