Urn was created by Geoff Johns and Paul Pelletier in the New 52 and made his first appearance in Aquaman #18.
Major Story Arcs
Keeper of the Prisons
Urn is the keeper of the Atlantean Prisons who lost three guards when Vulko launched missiles near Atlantis that started the Atlantean war. He is one of the guards watching Vulko, who is now held trial in the Atlantean prisons awaiting to be prosecuted. Before Aquaman enters the prisons to get seek Vulko's advice, he meets Urn who tells him that he would want the day of judgment to be forthcoming so that the dead can have their peace.
Powers and abilities
Urn is an Atlantean and possesses a number of metahuman abilities.
Like all Atlanteans, Urn possesses a degree of super strength
Like all Atlanteans, Urn possesses a degree of superhuman durability.
Like all Atlanteans Urn is able to normally function and move underwater, unfazed by the pressure, temperatures or lack of light.
Skilled Warrior (Swordsmanship)
Urn is shown as a skilled warrior against Scavenger's invading fleet, especially with his twin Atlantean blades
Urn is the warden of the Atlantean prisons and has several men under his command.
Weaponry & Equipment
Twin Atlantean Blades
Urn uses an Atlantean twin Atlantean blades as his standard weapons.