Dust, real name Rein Chelka, is a major supporting character in the Konosuba: God's Blessing on this Wonderful World! light novel series, as well as its anime & manga adaptions. Furthermore, he serves as the main protagonist of the spinoff series That fool is also in the spotlight! Give Blessings on this Wonderful World!.
Rein Chelka was a noble Dragon Knight from the kingdom of Braidle before his exile from the kingdom. He eventually settled in the town of Axel, which was located in the neighboring country Belzerg. Chelka took up the alias "Dust" and kept his past and true power secret from the people of Axel.
At some point he joined an adventuring party comprised of the crusader and leader Taylor, the archer Keith, and the witch Lean. He soon became known as an unsavory character as he more often than not displayed perverted and loutish behavior.
When Satou Kazuma came to town, Dust initially felt envious of the party he commanded, as it was comprised of three beautiful and seemingly powerful women. However, after spending one day with Kazuma's companions, Dust realized the burden Kazuma carried and the two became good friends.
Since then Dust has repeatedly been caught up in Kazuma's problems and social life, making powerful friends along the way. He has also become more admirable over time, although he is still nowhere near as altruistic as his former self.
Rein Chelka was originally a low-ranking noble from the kingdom of Braidle who became one of the kingdom's greatest Dragon Knights at a young age. He rode upon the back of Faitfore, an ancient and rare white dragon whom he saved from captivity.
Rein maintained a strong relationship with the Princess of Braidle, who eventually fell in love with him. One day the princess ordered Rein to kidnap her, as she didn't want to marry the man she was betrothed to. Rein agreed, and the pair left for two weeks before returning to the kingdom.
For his actions against the kingdom, Rein was stripped of all his titles and exiled from the kingdom, an act that caused his small noble house to collapse. He eventually made his way to the town of Axel in the neighboring kingdom of Belzerg, where he took up life as an adventurer named "Dust".
Dust neglected to tell anyone about his past, and the tale of his tryst with the princess spread, quickly became a favorite of young girls. He soon fell from grace, gaining a reputation as a lazy alcoholic pervert who spent half of his time in jail, although the exact reason for his personality shift is unknown.
At some point Dust joined a party led by a crusader named Taylor. The party consisted of Taylor, an archer named Keith who was almost as deplorable as Dust, and a witch named Lean. Dust took a liking to Lean as she reminded him of the princess of Braidle, and despite his rude and perverted comments, the two became good friends. Lean soon gained a reputation as Dust's carer, as she would often be forced to bail him out of prison or other precarious problems.
A Mysterious Child
While Dust was ordering food in the guild, a small girl came crashing through the window next to him. The girl, who was dressed in nothing but rags, stared resolutely at Dust and addressed him as master. Due to his reputation and the girl's appearance, the adventurers in the guild including his party assumed that the girl was some kind of sex slave of Dust's, and immediately set upon him. Before Dust could be harmed, the little girl came to his aid, managing to calm down the mob.
With the situation calm, Dust realized that the little girl was Faitfore in human form. Not wanting to reveal his past, Dust told his companions that Faitfore was the child of an old friend he was looking after. He left the guild with haste before anyone could pry into Faitfore's past and began wondering around town with the child.
Dust, not wanting to be deemed a child molester any longer, brought Faitfore clothes shopping and to the bath. Dust spent the next few days completing quests with Lean, Lolisa and Yunyun to pay for the insurmountable amount of food Faitfore was consuming. Taylor and Keith, who previously promised to assist Dust with his quests, had to retract their support due to unforeseen circumstances.
Dust has a very similar demeanor to Kazuma, especially in regards to their perverseness and laziness. He is famous for his delinquent behavior in Axel and has accumulated debts with multiple people including his own party members. He has purposely gotten himself thrown into jail many times simply because it was better than being outside, not minding his criminal record much.
Dust shows a particular lack of self-awareness similar to Aqua. He regards himself in a high standard and would often refuse to admit to his misgivings. He can also be very manipulative of others to do his bidding, particularly with Yunyun and Lolisa.
While on the outside he seems air-headed and ignorant to others, he is quite perceptive, being able to quickly piece together that the "little sister" Kazuma was talking about was actually the princess of Belzerg, and that he was worried about her betrothal.
He dislikes working hard and would often try and come up with quick money-making schemes, usually blowing up in his face later on. He comments about how hard-working and serious-minded people are hard-headed and are simply wasting their life away.
Despite his outward persona of a delinquent, Dust would display acts of kindness and genuine care for others from time to time, such as treating Yunyun to a meal or stuff toy and paying respect to the tranquility girl's victims.
Dust is particularly protective of Lean. Despite their constant banter and her very hostile attitude towards him, Dust has a soft spot for Lean. He would go out of his way to protect Lean in the slightest hint of danger and do what he can to make her happy, even to his detriment. This is attributed to Lean having a similar face to the princess in Dust's past.
Dust is well-renowned as one of Axel's strongest adventurers, however, his lazy personality somewhat stunts his potential. As noted by Chris and Princess Iris, Dust hides his true power from the people of Axel. The only time where Dust has actually displayed his true potential after his exile is during his battle with an enraged Faitfore. In order to save Lean, Dust punched the elder dragon, knocking Faitfore out with a single blow and causing shock waves to reverberate. Dust has a covenant with Faitfore, meaning that both of them are more powerful when around each other.
Dust's preferred weapon is a spear, however he has abstained from using them since his exile as some sort of vow to the princess of Braidle. Rein was said to be the most skilled spearman in his nation, commanding mastery of the weapon previously unseen. In some dire situations, Dust has fended off terrifying monsters with non-combat items by using them as makeshift spears.
Outside of martial abilities, Dust has a natural affinity for dragons. Rumors suggest that dragons have loved him since his birth, and he seems to have a deeper understanding of dragons than anyone else in Belzerg. Dust has displayed the ability to tame/get along with every dragon he has come across, forming instant bonds of friendship with some of them. His ability extends to other reptilian creatures.