Psi abilities
Psionic abilities are the "magic" of Underrail. They're combat abilities that require psi points to use, similar to "spells" and "mana".
Psionic disciplines
Psi powers are split into 3 distinct disciplines - Thought Control, Psychokinesis and Metathermics.
Thought Control
Thought control discipline is the most indirect of them all and it's also the hardest to get really good at. It is considered by many to be nefarious and mind controllers are often untrusted.
Ezra is the thought control trainer in South Gate Station. He can be found on the SGS level 7 cyber labs. You can also learn Bilocation from the Mysterious Pillars in Silent Isle.
Psychokinesis
The psychokinesis discipline is similar to telekinesis with additional electric powers.
Bisson is the psychokinesis trainer in South Gate Station. He can be found on the SGS station platform.
Metathermics
Metathermics is the area of psionic development that deals with instigating rapid temperature changes and chemical reactions. Metathermic abilities consist mostly of attacks that deal heat or cold damage and their side effects.
Quinton is the metathermics trainer in South Gate Station. He can be found on the SGS agronomy level.