Arniel Gane

Arniel Gane, of The College of Winterhold, is a researcher of peculiar magics. He leads an excavation at the tomb of Saarthal and experiments with Soul Gems, the latter of which he is highly secretive. Arniel is located in the first room on the right on the second floor of Hall of Attainment.

Under Saarthal
After the Dragonborn's first lessons as a new student of the college, Tolfdir and the other apprentices venture to Saarthal to assist Arniel with his excavation. Upon arriving, the Dragonborn is tasked with collecting three Enchanted Rings and an amulet. Performing the errand lands the Dragonborn imprisoned behind sturdy iron bars. Upon being freed, Tolfdir and the Dragonborn investigate a hidden tunnel in the tomb, eventually coming in contact with a member of the Psijic Order.

Enchanted Rings
After discovering the Eye of Magnus in the rooms below the tomb, the Dragonborn returns to inform Savos Aren. Any time after this event, the Dragonborn can give the Enchanted Rings to Arniel, but it is not required.

Containment
Arniel helps the Dragonborn and Faralda defend Winterhold against Magic Anomalies in Containment. During the battle, he will not use magic, instead relying entirely upon unarmed combat. Except to reanimate a dead citizen.

Arniel's Endeavor
As part of a secret experiment, Arniel tasks the Dragonborn with retrieving ten Dwemer Cogs. Find the artifacts, the Dragonborn must then contact Enthir about a Warped Soul Gem Arniel wanted from him. Enthir was reluctant to provide the item to Arniel, but relents if the Dragonborn retrieves a staff Enthir accidentally sold to a necromancer at Hob's Fall Cave (locations may vary). Enthir surrenders the gem after the staff is returned to him. This eventually allows the Dragonborn to use the Warped Soul Gem in a Dwemer Convector three times, along with Arniel's Convection.

Fate
Arniel disappears as a consequence of his research with the Warped Soul Gem. As a reward for the Dragonborn's efforts, however, Arniel grants the Dragonborn with the ability to summon his shade in battle. Arniel Gane’s shade can be seen wandering the area around The College of Winterhold after his quest line has been completed.

Quickly increase sneak skill

During the Saarthal excavation quest, find Arniel in the mine and equip a dagger. Then sneak up on him and you can continue to do sneak attacks on him until your sneak skill increases to 100. His life replenishes automatically over time. The entire process can take less than an hour to max out your sneak skill.

Quests

 * Arniel's Endeavor
 * Containment
 * Under Saarthal