Gideon is an enemy in Octopath Traveler. He is a scholar who kidnaps people in Quarrycrest Mines and extracts their blood in order to create blood crystals, a technique learned from a copy of the tome Cyrus searches for. He is the boss of Chapter 2 of Cyrus' story.
Before Cyrus's arrival in Quarrycrest, Gideon captured multiple people to use their blood for a dark ritual from a translated version of From the Far Reaches of Hell. As he is returning to his ritual chamber in the Quarrycrest Sewers, he confronts Cyrus and engages him in battle, only to be defeated and killed. The abridged tome he had was taken by Cyrus to be researched further into the original's theft.
- Animate Bones: Summons two Dancing Bones to protect him.
- Hands of Darkness: Deals heavy dark damage to the whole party. May cause Blindness.
- Creepy Laugh: Lowers physical and elemental attack of the whole party temporarily.
- Executioner: Deals heavy physical damage to one party member.