Gideon

Gideon is a psyker found in the Master's lair

Background
Gideon is one of four psykers, the others being Moore, Lucy, and Wiggum. He is kept behind a force field in the Master's lair beneath the Cathedral. He is one of the Master's failed experiments in trying to awaken psychic powers in Humans.

Gideon is the most comprehensible psyker, and is able to give the Vault Dweller some background information on the "Corridor of Revulsion." While he wears a psychic nullifier to suppress his powers, his hands still glow with a strange energy.

Appearances
Gideon appears

Behind the scenes
According to the Fallout Bible, Gideon is "receiving-telepathic-dominant with minor photokinetic abilities."