Eternal Champion

The Eternal Champion in main protagonist in The Elder Scrolls: Arena.

History
Emperor Uriel Septim VII summoned his Imperial battlemage Jagar Tharn due to rumors of treachery. Tharn betrayed him and transported Uriel Septim VII into another dimension using an ancient and powerful artifact, the Staff of Chaos. Tharn's apprentice, Ria Silmane, witnessed all of this and tried to warn the Elder Council. But, before doing so, Jagar Tharn killed her. After months of planning, he transformed himself into the image of the Emperor and took the throne. He summoned demon minions and transformed them into the Emperor's Guards. He also sent a low-ranking member of the emperor's court in the dungeon to die.

Ria Silmane, however, wasn't truly dead. Through extensive use of magic, she managed to stay on this world to warn the prisoner of Jagar Tharn's treachery and that the Emperor was in fact Jagar Tharn. Ria created a key for prisoner's cell so that they could escape. The only way to stop Jagar was to obtain the Staff of Chaos. The problem was, the Staff has been split into eight pieces by Jagar Tharn and scattered across Tamriel. Since the prisoner was the only one Ria could trust, it fell to them to reassemble the Staff of Chaos and to defeat Jagar Tharn.

Finally, in 3E 399, after a long quest to reassemble the Staff of Chaos, the Champion reassembled the Staff. Each piece was located deep in the dungeons of each province. However, the Staff wasn't complete, as the Champion and Ria had hoped. There was still one piece in the Imperial Palace, the jewel of the Staff. The prisoner fought their way through Imperial Palace and finally reached basement where Jagar Tharn was, along with the jewel. The Champion touched the Staff's jewel and caused Jagar Tharn to melt. Automatically, the Staff of Chaos opened a portal to the dimension where the Emperor Uriel Septim VII and General Warhaft were being held. The Emperor than gave them the title The Eternal Champion for saving him, his general and defeating Jagar Tharn.

Fate
The Champion's fate is left unknown at the end of Arena. It is thought, however, that the Champion returned to their home province greeted as great hero. Uriel Septim VII also claims that he would rule by his side, implicating the Champion might have been given some form power over the Empire.