Darui is a jounin-level shinobi from Kumogakure. He is also the Commander of the First Division of the Allied Shinobi Forces.

Darui is portrayed as being easy-going and mellow; when compared to the Fourth Raikage's over-the-top exit through a window, he tells C that he'll just use the door. Whilst having a laid-back demeanour, Darui isn't lazy, leaping to the Raikage's defence when the bodyguards of the other Kage overreact to the Raikage's actions. He also has a habit of referring to things or events as being "dull" a play on his name. Darui is also very apologetic, even apologizing for other people's actions, a trait he'd never noticed himself; this attribute led him to say "sorry" just as much as "dull." He is also very loyal to the Raikage who considers Darui his "second right hand." He adresses the Raikage with "boss" rather than "Raikage-sama."

Darui is fairly tall in stature and has a dark skin tone, slightly bulbous nose, a lazy look in his eyes and white, shaggy hair which covers the left side of his face. He wears a high collared sleeveless uniform, loose fitting pants, and one-strap-over-one-shoulder Flak Jacket of a Kumogakure Jōnin. Darui also has stylized characters for Water (水) and Lightning (雷) tattooed on his right and left shoulders respectively, denoting his chakra's elemental nature affinities; Water Release and Lightning Release. The tattoo on his left arm also signifies that he has inherited the Third Raikage's technique. As a sword-user, Darui wields a broad, cleaver-like blade, which he carries on his back. He doesn't seem to carry it around with him in his village however.

Darui is a highly skilled and capable shinobi. He learned how to create Black Lightning under the tutelage of the Third Raikage, making his lightning techniques even more powerful. His chakra reserves are great enough to not die of chakra exhaustion after using three of the Treasured Tools of the Sage of the Six Paths and still have enough chakra left to continue fighting. His abilities have earned him the praise and recognition of the Fourth Raikage himself, who appointed Darui as his personal bodyguard and considers him his right-hand man.

Kenjutsu

Darui wields a long and fairly broad sword that is peculiar than others swords as it folds in two to be sheathed and unfolds when in use. He has shown exceptional skills in kenjutsu, as he was able to clash with Suigetsu Hōzuki's Kubikiribōchō and easily overwhelm and pin him to a wall with his lightning imbued sword. He was also skilled enough to literally disarm Ginkaku and Kinkaku during their battle, and knock Ginkaku into Kinkaku's Kōkinjō while quickly seizing the Shichiseiken and Benihisago.

Darui is proficient with water and lightning release techniques, and is able to use two separate techniques of the natures simultaneously. He uses Lightning Release: Wave of Inspiration, together with water release jutsus to let electricity flow through the water and make the jutsus deadlier. He has shown exceptional skills with Lightning Release techniques individually, able to use Black Lightning, a special form of lightning passed down to him by the Third Raikage. With the power of the "Black Lightning", he could use techniques like the Lightning Release: Black Panther to immobilize and/or kill several enemies. According to one of his comrades, he is the only person to have inherited the Third Raikage's Black Lightning.

Darui is also proficient with the use of chakra flow with ballistic weapon. His skill with chakra flow is such that he was able to cut through a metal blade with a lightning-enhanced shuriken.

He also possesses the kekkei genkai known as Storm Release, which combines both lightning and water chakra to create beams of light that can be freely guided like missiles and cause powerful explosions.

(Source: Naruto Wikia)