Jagar Tharn ( Arena ) Jagar Tharn was an Imperial Battlemage and personal adviser to Emperor Uriel Septim VII during his earlier years as emperor . After months of plotting , Tharn used the Staff of Chaos to trap Septim in Mehrunes Dagon ' s Plane of Oblivion out of jealousy and desire for the throne , and copied his look by using Illusion magic . Tharn usurped the throne as Emperor of the Septim Empire of Tamriel from 3E 389 until his ultimate demise in 3E 399 at the hands of the Eternal Champion , by the unification of the Staff of Chaos and the Jewel of Fire ' s power . Tharn served as the main antagonist of . Background . Tharn ' s earlier life before Imperial service has been left mostly ambiguous . What is known about Tharn ' s younger life is mostly what Tharn had claimed : he was born in southern Valenwood , to a Wood Elven mother . According to " The Real Barenziah , Book V " , Tharn was a Dark Elven / High Elven mix , Symmachus also stating that he was " . . . part the gods only know what . " Tharn couldn ' t be a Breton , due to it being said that Human blood was absent from him , leading to the former statement of him being born in Valenwood to be true . He claims to be the heir of Moraelyn . Tharn was also a mage - priest at the Temple of Sethiete in Camlorn , High Rock . He turned to thievery for a short period of time after leaving the temple ' s circle , stealing many books of old , powerful and forgotten spells , along with lore and articles about many ancient tools and magical items , including the Staff of Chaos , an immensely powerful magical staff said to be made with the land itself . In 3E 376 , Tharn had traveled to Mournhold under one of his alter - egos , an enigmatic bard named Nightingale , and stole the Staff of Chaos from its hiding place in the Mournhold mines . An ambiguous stretch of time later , Tharn managed to become the Imperial Battlemage and adviser of Uriel Septim VII . In 3E 389 , Tharn used the Staff of Chaos to trap the Emperor , and banished him to Mehrunes Dagon ' s plane of Oblivion . After Ria Silmane threatened that she would warn the Elder Council of his treachery , Tharn used the staff to eliminate her corporeal form . Tharn , using Illusion magic , took the Emperor ' s appearance and usurped the throne of Tamriel , and replaced the Emperor ' s guard and servants with Lesser Daedra and other foul creatures , also using Illusion magic to hide them as humans so no one would suspect that the original guard were missing . After , he split the staff into eight perfectly formed pieces , as the land split itself . He then drained the pieces of the staff of its power , and put it into the Jewel of Fire , as a sustainable lifeforce . The only fallacy with his plan would ' ve been the true emperor , Uriel Septim VII , himself . Normally when the Emperor of Tamriel dies , the Elder Council is magically informed by the Amulet of Kings and meets to select a successor . By imprisoning Septim in another dimension where time ran slower , Tharn prevented this from happening . He then shattered the staff into eight pieces , which Ria Silmane explained was done by Tharn " splitting the land , " and hid them in all of Tamriel ' s provinces , excluding the Imperial Province . In 3E 397 , Tharn and Shadowmage Pergan Asuul tried to manipulate the War of the Bend ' r - Mahk to create the Shadow of War , the powerful creature known as Umbra ' Keth . However , a mysterious hero with the help of Skelos Undriel and Azra Nightwielder , thwarted his plan . One year later , in 3E 398 , Tharn made a bargain with Mehrunes Dagon to invade the Battlespire , the Imperial training facility and bastion of the Imperial Battlemages . Essential to protect himself , Tharn had to eliminate any and all threats to his reign . As some circles of battlemages were aware that Tharn was impersonating the emperor they clearly posed a threat . Mehrunes Dagon was defeated and cast back into Oblivion by a mysterious hero , but the Battlespire was destroyed . The Imperial Battlemages were no longer capable of thwarting Tharn ' s reign . Tharn ' s reign ended in 3E 399 . The Eternal Champion , with the help of Ria Silmane and Lady Barenziah , managed to gather the eight hidden pieces of the Staff of Chaos . During the final battle , in the depths of the Imperial Palace Dungeon , the Eternal Champion managed to unite the Jewel of Fire with the Staff of Chaos , a jewel that held Tharn ' s lifeforce . Jagar Tharn disintegrated into fire - like ash and liquid , his clothes burning with him . Uriel Septim VII was saved , and declared the hero the Eternal Champion of Tamriel . Interactions . Imperial Palace . At the fourth level of the Imperial Palace , Tharn will fight the Eternal Champion on sight . After having his health fully depleted , Tharn will encase himself in a magical shield , resembling a turquoise bubble . In order to finally defeat Tharn , the Champion must pick up the key on Tharn ' s body when he is defeated , or find the spare Mithril Key in the of the cells , and unite the Staff of Chaos with the Jewel of Fire . Doing this will cause Tharn to disintegrate , and the final quest is finished . Combat . Tharn is the most powerful enemy in " Arena " . The following is combat info from the Codex Scientia :