These are the characters who can provide Scarlett with training in new Mental Skills for use in Necromantic spell casting, or improve her level of mastery of skills she already knows, if Scarlett has the necessary Skill Points (earned through Experience) and prerequisite skills.
Not all teachers know all Mental Skills. Scarlett can only learn new Skills (or improve her Level of Mastery of existing Skills) from a Teacher who knows that skill. See the article on each teacher for which skills they can teach.
- She finds a Teacher who teaches that Mental Skill.
- She has accumulated sufficient Skill Points.
- She has learned the necessary prerequisite Mental Skill.
To learn a new Mental Skill or improve the Level of Mastery in an already-learned Mental Skills, Scarlett should move close enough to the Teacher character so that the "Talk to ___" Contextual Action Prompts appears. Initiating a Conversation with a Teacher will provide additional Dialog Choices. The first time Scarlett speaks with any Teacher, the Teacher will first introduce themselves. (Not all Teachers will automatically train Scarlett in Mental Skills; some, such as Nox, will demand Scarlett perform a Quest first. Others, such as Aeris, will only provide training after she has moved to the Net of the Mask Guildhall.) Eventually, one of Scarlett's possible Dialog Choices with a Teacher will be to "Learn Mental Skills". Selecting that reply will bring up the Mental Skills hierarchy screen.
Mental Skills that Scarlett can learn or improve with the current Teacher will be highlighted with a pulsing glow on the Mental Skills screen. (Furthermore, Mental Skills will only be so highlighted if Scarlett as the necessary prerequisites. E.g., after Earning Nox's Trust, Scarlett will very probably wish to learn the Blood Toll spell; but that won't be available until she has first learned at least one Level of Mastery in the Ancestral Horror spell.)
To learn an available Mental Skill, select it from among those that Scarlett can be learn and press the action key/button to buy an item. A pop-up display will confirm the action, showing the details of the Skill at the Level of Mastery to be learned and its cost in Skill Points. (That cost appears to always be 10 for every Skill.) Learned Mental Skills are displayed in color on Scarlett's Skills page and the costs deducted from her Skill Points total.