Rufus' tribe is known as the Haros. The Haros are demons native to the Underworld, and whose warriors, the bounty hunters, are charged with protecting the balance between Aernas and the Underworld. They have the ability to deal with evil souls and either send them back to the Underworld's prisons or extinguish them forever, depending on the circumstances.
In the Taiwan server, Rufus is incorrectly classified as a Human/Demon hybrid.
Rufus is known to be Lass's half brother. A side-by-side Lass and Rufus official art shows that their faces look the same, though their hair styles are different.
Like Lass, Rufus also has possession of the power known as the blue flame. This is evidenced in one of his official artworks, but even though he has significantly more control over it than his brother, he is never seen using it in game.
According to a Brazilian article, Rufus is said to resemble his father Legis in not only appearance but also ability.
Rufus has a prosthetic left arm, indicated by the blue line running all the way from his shoulder down to the back of his hand. It is an injury caused by Berkas.
Strangely, despite Rufus's personality, his first meeting and subsequent dialogues with Lass in the Hero Dungeon, Wizard's Labyrinth show him always being the first to initiate conversation with his brother. During the few scenes they share, neither seems to display any form of hostility towards each other, and Lass does not show knowledge of knowing who Rufus is to him.
As a bounty hunter who hunts down souls that escape from the Underworld, Rufus may have some sort of enmity towards Ley, who is a vessel for both her own and Edna's soul as a result of a ritual by Zero's master, Oz, to save her life when she was critically ill. This is shown when he attacks her in the Wizard's Labyrinth.
Rufus is the first character to be released with all 4 of his jobs. However, he was released with only his 1st job in North America and Philippines, releasing a job one after another every week.
Rufus is known as "Lupus" in the Korean and Taiwan servers and "Luxus" in the Philippines server.
Rufus is one of three characters who specializes in machinery, the other two being Mari and Lire. In Rufus's case, most of his weapons are firearms, which are technologically-powered tools.
Like Arme, Ronan, Lass, Sieghart, Dio, Zero, and Ley, despite the fact that darkness is shown in this game as evil and that demons are generally viewed as such, Rufus uses his powers for the benefit of others, albeit for a monetary price, rather than out of his good will.
Rufus's family, along with Elesis's family, are the only ones with the most number of members revealed. Coincidentally, both families have exactly two members within the Chase itself (Rufus and Lass for the Wilde family; Elesis and Sieghart for the Sieghart family) and both families have a father who is missing (Legis for the Wilde family; Elscud for the Sieghart family).