Three-Eyes is a member of the and a trainer of the Artificer specialization.
He can only be encountered if The Inquisitor is a Rouge.
Involvement
After completion of the Specializations for the Inquisitor war table operation, three trainers will appear at Skyhold, and if the Inquisitor is a Rouge, Three-Eyes will be one of them.
Trivia
Three-Eyes is an associate of Varric's.