Vilkas

Vilkas is a Nord werewolf and a resident of Whiterun. He is a member of The Companions and The Circle, the secret order within The Companions. He serves as the Dragonborn's shield-brother in several of the Companions' quests. As with all Companions, he is usually found within Jorrvaskr, located in the Wind District of Whiterun.

After the Companion's questline is completed, Vilkas will eventually give the quest Purity. In this quest, he will ask the Dragonborn to cure him of beast blood. He is available as a follower and also eligible for marriage after completion of The Companions questline. Vilkas can also be selected to act as steward for the Dragonborn.

Quests

 * Take Up Arms: Prove that your worthy to join the Companions.
 * Purity of Revenge: Retrieve the Fragments of Wuuthrad and wipe out the Silver Hand.
 * Glory of the Dead: Cure Kodlak Whitemane's spirit and prove to be a true Companion.
 * Purity: Help a member of The Circle give up their beast blood.
 * Escaped Criminal: Track down and kill an escaped prisoner.

Background
Vilkas and his brother, Farkas, were both raised in the Companions' Hall. Their father, Jergen, left them there while he went to fight in the Great War and never returned. Eventually, Vilkas and Farkas both officially joined the Companions. They were said to be the youngest members to ever join, though this may be a play on words by Vignar, referring to the twin's young age during their residence at the Companion's Hall rather than the age at which their membership became official.

Personality
At first, Vilkas seems to think the Dragonborn isn't worthy of being a Companion, but he eventually warms up to the idea after the completion of Glory of the Dead. Vilkas is well-spoken and considered to be an intelligent man by the other Companions, the counterpart to his brother's physical prowess. Vilkas, along with his brother Farkas and Kodlak, resists the call of the beast-blood, choosing instead to refrain from transformations. However, he struggles with the side-effects more harshly than the others.

Vilaks is also thought of as a hot-tempered man. For example, during Purity of Revenge, he does not hesitate to avenge Kodlak's death. However, he does later show remorse for his rash actions, as seen in Glory of the Dead, during which he refuses to complete his journey to Ysgramor's Tomb, feeling himself unworthy.

Trivia
. Therefore if you want improvements, or you want to buy materials, you have to travel to whiterun.
 * If Vilkas is a follower, the Two-handed skill can be trained in for free. Buy training, then check his inventory and take the money back.
 * Vilkas usually says that he likes and prefers two-handed weapons, and he always uses them when he is the Dragonborn's follower or when he is in a quest. However, Vilkas used a one-handed sword and a shield when training against the Dragonborn in the quest, Take Up Arms.
 * Vilkas may be randomly encountered out in the wilderness killing an animal along with Ria or other Companions.
 * If Vilkas is a follower, he will leave if the Dragonborn assaults or murders an innocent civilian, just like his brother, Farkas.
 * Vilkas' name is likely derived from the Latvian word "vilkacis," meaning "werewolf."
 * In Lithuanian, the word "vilkas" means wolf.
 * He has claimed to have killed every type of creature in Skyrim and thinks a trip to Morrowind is in order.
 * If Vilkas is appointed as steward, he may return back to the Jorrvaskr