Vanitus and Karux are a pirate-based Titan BIONICLE custom-made for the MOC Pirate Theme Contest of February 2013 on Brickipedia. Vanitus is the Pirate, and Karux is his Rahi partner in crime known as a Parraxius; a parrot-like rahi beast with a variety of possible birth-given abilities. (the species is not canon) They are both non-canon characters.
This MOC had a specific kind of pirate chosen for its construction; Pirates that know how to take advantage of every situation. His notable feature is his Kanohi Rode, which makes him unique among many MOC pirates in a very notable way. The MOC was inspired by the Toa Lhikan and Kikinalo limited edition titan set, as evidenced by a Toa with a Rahi.
Back Story - The Early Years of the Pirate
Vanitus was once the Toa of Air, and leader, of a disbanded Toa team around the same time that the Toa Mangai were fighting the Toa-Dark Hunter War. He knew how to trick an enemy easily, as he learned when he was a Matoran that there are some who will do anything to stand in the way of a Toa. As a Toa, he wore the Kanohi Rode, the Great Mask of Truth. He had a relationship with an unnamed female Toa of Earth on his team that had to end when the Order of Mata Nui recruited him to work with them. He was there for a month before backstabbing them by getting a member killed by a Makuta he made a deal with three weeks prior to the betrayal. He then joined the Brotherhood of Makuta not long afterwards after going into hiding for a while.
Back Story - From Makuta to Dark Hunter
When Vanitus became a member of the Brotherhood of Makuta, he was given a Rahi ally to accompany him called a Parraxius. He named it Karux, and quickly learned how to cheat people with it. He has never been caught using his Rahi companion to do this by any Makuta. He remained loyal until Teridax was killed by Mata Nui in the final battle on Bara Magna. He lost his faith in the Brotherhood, and joined the Dark Hunters, where he began swindling his new master - The Shadowed One - with replicas of his rewards from a job that looked so real, even the Shadowed One himself would believe it was real, when in truth every duplicate was a counterfeit created by his Parraxius given to him by the Brotherhood of Makuta. He officially became well known by the Order of Mata Nui as the only Pirate among the Dark Hunters to remain a member. The only others were the six former member Piraka, but they left the Dark Hunters and were imprisoned on Daxia compared to this successful former Toa.
In battle, this former Toa wielded a specially forged lightning sword with a hook-shaped hilt. Being a Pirate, he abused the power of the Kanohi Rode he wears to get whatever he desired. Immediately after, his Parraxius would duplicate it so he could keep the originals for himself.
Vanitus' partner in crime. This Parraxius was born with the ability to make realistic counterfeits of whatever it looked at and completely memorized. It was a flightless Rahi beast, which made it hard to travel the grounds of Bara Magna. often. Other than this, there is no other information on Karux.