Appearance:
Lintence is notable for his dark-green, wavy and volumed hair style. He is mature, has slit-eyes and usually wears a serious look. He dons a long, black coat over a white shirt that is untucked, over black pants. His shoes are black cowboy boots. It is also noted that he wears black glovelettes.

Personality:
He has a very serious and hostile demeanor. To fully utilize his skills, he would travel to cities and seek the environment to fulfill it. After days and months of wandering for over five years, he arrived at Grendan.

Skills & abilities:
Lintence wields the Heaven's Blade-Gloves. Using his incredible martial arts capabilities, he used his kei to create some of the largest and intricate steel wires to trap filth beasts like a spider, capable of splitting the steel wires to fatally cut through large filth beasts and can even create a circular cell to contain them if necessary.
For unknown reasons, he mentored his Steel Wire skills to Layfon "Wolfstein" Alseif and helped train him into the fighter he is today. His competence as a mentor is far greater than Layfon, since the number of steel wires Lintence could amount to is known to be tens of thousands to hundreds of millions.

source:wikia

She is the Sub-Master at Bee Hive.
In her flashbacks, she was shown as a childhood friend of Gauche and even holding a crush on him when they were Letter Bees.
Her appearance has differed ever since assuming her post as the Sub-Master.
Aria's shindan is the violin, which she plays to either heal or attack.

Jiggy is the adopted older brother of Nelli and Nero. He is the only Express Letter Bee and has a strong heart, enough to power his Shindanjuu motorcycle, which he rides as his mode of transport.

Dr. Thunderland Jr. is a biologist whose forte is pathology and doubles as a medical doctor at the Bee Hive.

Spoiler start|Due to his gathering of corpses for autopsy, it derived him the nickname "The Corpse Doctor". In spite of that, he has a kind nature towards every living thing that he dissects, which is implied by the display of little memorials in his laboratory.

At one point, he played a part with Gauche in inspiring Mana Jones to complete her research, which she had initially given up due to her sudden visual impairment in an accident.

He is also one of the six who survived the government airship crash on the Day of The Flicker. |spoiler end

Signales is the gatekeeper at the Yuusari Gate of the Bifrost Bridge and employs the same method as Signal for verification at the gate. Twelve years prior, he was one of the triplets aboard the government airship when it crashed on the Day of the Flicker and one of the 6 people who survived the incident.

Signal is the gatekeeper of the Kyrie Gate at Bifrost Bridge. He uses a method whereby a pipe is used to verify the identity of a person who wants to cross the bridge. His former name was Camus and used to be a Letter Bee. Twelve years prior, he and his other two brothers were aboard the government airship when it crashed on the Day of the Flicker. He was a substitute in place of Largo Lloyd and was one of the 6 people who survived the incident.

Lawrence, AKA "The Man Who Couldn't Become Spirit", is the leader of Reverse.

He is a fourth-year student and the oldest of the 17th platoon. Sharnid is an excellent sharpshooter who is usually laid back and enjoys teasing other people. He also appears to have playboy-tendencies. It is revealed that he was originally a part of 10th Platoon
His main DITE is a rifle, but he later obtains two close quarters pistols from Harley in order to take up multiple roles in their small platoon.

Source: Wikipedia

She is a first year student of the Military Arts Department, a tall girl who is a friend of Mayshen and Mifi. Her dream is to become a police officer. She became friends with Layfon after he saved Mayshen at the inauguration incident. She has a strong sense of justice and works for the police department of Zuellni.

Source: Wikipedia