Vertida Sefalatis is a member of the Sanguinesti division of The Myreque. He is first seen in the quest Darkness of Hallowvale, when the player arrives for the first time in the Myreque Hideout. He is the only one in the hideout at the time, and asks you who you are and what you want. When you explain your reasons, he calms down a little and tells you to talk to his leader, Safalaan Hallow.
Vertida seems to be a very good ranger, and has a bow and a quiver of arrows strapped to his back. He can always be found in the war-room of the Myreque hideout in Meiyerditch. He appears to be second in command to Safalaan in the Sanguinesti order of the Myreque.
After completing A Taste of Hope, Vertida will sell you Ivandis Flails for 20,000gp each.