Elontir

Elontir was a young High Elf Mage in training who was exiled from Ulthuan after an incident in the White Tower of Hoeth lead to the dead of a fellow pupil and the cripling of one of Elontir's teachers. He traveled to the Old World, joining the Imperial forces in the Great War Against Chaos in an effort to achieve redemption and end his bitter exile.

History
Born to a life of power and privilege, Elontir, even as a baby, showed that he was naturally powerful in the Winds of Magic. He was sent to study in the White Tower of Hoeth, where his natural talents were complemented with skill. It seemed like he was destined to take his place among the Archmages of the White Tower, and Elontir's arrogance grew along with his talents. But Elontir's attitude earned him a bitter rival. Their bickering escalated until they had a magical duel, which ended disastrously with Elontir's rival dead and one of his teachers crippled. As punishment, Elontir was banished from Ulthuan until he atoned for his crime. With nothing to his name but for a few magic Tomes and the clothes on his back, Elontir sailed to the Old World looking for adventure.

Sometime later, Elontir found himself in the Empire of Man, where he heard news of a Chaos invasion led by Asavar Kul, the Everchosen of Chaos. At first Elontir thought little of it, for his people had been fighting the Dark Gods for thousands of years. But then he learned that Teclis, Hoeth's greatest living archmage, had traveled to Ulthuan to assist the Empire. Teclis had distinguished himself during a simultaneous Chaos-Dark Elf invasion of Ulthuan, and had sailed to the Old World to relieve the humans from their shared foe.

Seeing a chance at being redeemed in the eyes of his people, Elontir rushed north and offered his services to Magnus the Pious, who was leading the Imperial army. Despite the Empire's prejudice against magic users, Magnus accepted all magic users who wished to fight against Chaos under Teclis' advice and Elontir was accepted into the ranks of the army. Despite his selfish intentions, Elontir was determined to prove his worth or die in the attempt and fought bravely along with Magnus against Daemons and Kul himself. After the battle was won, Elontir was hailed as a hero, but no pardon was offered by Teclis. Magnus offered him to join his personal retinue, a position of great power and influence as Magnus was likely to become the next Emperor. Elontir cared not for the politics of humans, but accepted the position as a way of improving the opinion of Teclis. A mage with the fame of Teclis could end his exile with but a few words, and so Elontir came south to Nuln determined in gaining his favor, no matter the cost. If that cost was assisting Magnus and Teclis in their quest to safeguard the Empire, that was a price he was willing to pay.

Source

 * Warhammer: Chaosbane