Eivor is the first name of the Viking protagonist in Assassin's Creed Valhalla.
Eivor leads the Raven Clan from Norway to England during the ninth century. The character can be presented as male or female through player choice, while the name Eivor remains central to the protagonist's identity and the story's historical setting.
The campaign follows the clan's attempt to establish settlements and alliances in England. Eivor also becomes involved with the Hidden Ones and the Order of the Ancients, linking the Viking narrative to the series' Assassin-versus-Templar mythology.
Sigurd is Eivor's adoptive brother and an important supporting character, not the protagonist. Ragnar is a famous historical Viking associated with other stories, and Ubba is one of several Viking figures encountered in the game. Those names should not replace Eivor in this answer.