Character skills can be obtained not only by purchasing from NPCs but also through monster drops or crafting.
You can purchase the following skillbooks from NPCs in villages:
[SkillBook Merchant]: Purchase skillbooks for each class with Gold.
[Naval Battle Guide Merchant]: Purchase ship skillbooks with Gold.
[Mercenary Trainer]: Purchase tactical manuals (shared across characters) with Delphinad's Stars.
[Naval Warfare Manual Merchant]: Purchase the passive ship skillbook "Warfare Manual" with Delphinad's Stars.
[Guild Merchant]: Purchase class skillbooks with Tokens of Unity.
[Wandering Merchant Daru]: Purchase skillbooks with Wicked One's Remnants.
In addition, by long-pressing the skill icon in the top-right skill menu in the game,
you can view the skill’s information and how to obtain it.
▶ Related FAQ Links
☞ [I want to auto-use skills.]
☞ [What are Ancestral Skills?]