Avitus is a Devastator Marine and a Sergeant of the Blood Ravens Space Marine Chapter who has served in both the 3rd and 4th Companies. He fought in the Kronus Campaign, the First Aurelian Crusade and the Second Aurelian Crusade under Captain Davian Thule and the Force Commander Aramus.
Avitus grew up in a small settlement on the Jungle World of Typhon Primaris. Among the Astartes of the Blood Ravens' 4th Company he was known as a hard man who despised weakness and Traitors. He was also known to have an extreme dislike for the Imperial Guard due to his experiences with them as a child and his hostile relationship with several of their regiments during prior campaigns.
During his childhood, before becoming a Space Marine, Avitus' primitive settlement on Typhon Primaris was subjected to the cruelty of a corrupt Imperial Guard regiment. The settlement was extorted to near-starvation by unofficial taxes and penalties. This is believed to be one of the first causes of his well-known hate for the Imperial Guard.
The Kronus Campaign
During the Kronus Campaign, Avitus fought against the 1st Kronus Liberators at Victory Bay. During the fierce fighting, he lost two squad mates to those he believed were Traitors to the Emperor. This bloody fighting ingrained in him the attitude that all Guardsmen are Traitors and weaklings.
The Aurelian Crusades
Sergeant Avitus fought in both the First and Second Aurelian Crusades, leading the 9th Devastator Squad. During the First Aurelian Crusade he once again served under Captain Davian Thule, and later, Force Commander Aramus, and helped them defend the Sub-sector Aurelia from an encroaching Tyranid splinter Hive Fleet. During the Second Aurelian Crusade, while still serving under Aramus, Avitus helped defend the sub-sector from an incursion by a large warband of Black Legion Chaos Space Marines.
Canon and Possible Betrayal
In Dawn of War II - Chaos Rising, Avitus is a possible traitor, along with Martellus and all the other members of the Blood Ravens squad under the command of Force Commander Aramus. If he is revealed as the traitor, he is slain by Sergeant Tarkus. Dawn of War II - Retribution also hints that he was the canonical traitor, as Sergeant Tarkus takes a vow of silence and explains he took the vow primarily because he had killed a friend from Kronus during the Second Aurelian Crusade. Tarkus reveals this when he breaks his oath aboard the Space Hulk Judgement of Carrion. Since only Davian Thule and Avitus fought along with Tarkus on Kronus, and Davian Thule can not be corrupted, it is likely that Avitus was the canon traitor among the Blood Ravens.
Avitus was a dour and cruel warrior who held no mercy or compassion for the unaugmented masses of the Imperium following the campaign for Kronus and the deadly battle the Blood Ravens fought against the stubborn Imperial Guard there.