Avulstein Gray-Mane is an NPC in the game The Elder Scrolls V: Skyrim
Avulstein Gray-Mane is the son of Fralia Gray-Mane
You meet him in the quest Missing in Action
His brother was kidnapped.
When you enter Fralia's house, Avulstein is aggressive at first, but then calms down when he learns you have come to help.
He becomes your follower in the quest and help you free his brother from Northwatch Keep