Some changes made to how the names are spelt.
Much thanks to Anonymous, Elphie and scorpion1d3x!

scorpion1d3x has also compiled a list of the voice actorsin the Corseltel Drama CDs here:
http://goingsoloonce.livejournal.com/15907.html?thread=149795#t149795


Here's a list of characters in Corseltel for easier reference.

Characters:
Marciel – Has ability of all 7 kinds of dragon magics. Caring for 7 baby dragons.
Nata - dark, oldest, mature
Sata - wind, second oldest, mischievous
Ata - earth, third oldest, responsible
Mata - water, fourth oldest
Tata - wood, fifth oldest, a little trickster
Hata - fire, poor sense of direction, mild tempered compared to other fire dragons
Kata - light, youngest

Earth
Knowledgeable, loves reading books, have a strong sense of responsibility. Capable of lifting very heavy things, by altering their weight.
Ranbalus – Earth dragon mage. Entered Corseltel on his own after wife and daughter died, and became a dragon mage.
Yuicy - Very mature, has a crush on Ranbalus. Takes care of the other earth dragons when Ranbalus goes on long journeys.
Rorby - Second eldest after Yuicy. Likes Erize.
Lido
Kuretto
Others:
Kuroe - 8th earth mage, v4

Fire
Almost all have poor senses of direction and hot tempers
Iphrov – Fire dragon mage. Bad at expressing his own feelings, also has a poor sense of direction. He has a wife outside Corseltel, who has since died. Brought daughter Argina to Corseltel.
Argina – Fire dragon mage trainee. Hot blooded, poor sense of direction, gets along well with the mild tempered Hata. She admires Marciel a lot.
Meo - He has the best sense of direction out of all of them. Interested in pottery making. Most think his works look strange.
Rita - Also hot tempered. She cares much for Argina, and is jealous that Argina gets along better with Hata then the rest of them. Her interest is glass making.
Mano
Suu
Others:
Fina – Iphrov's wife, Argina's mother
??? - Iphrov's first trainee dragon who went back to the dragon tribes after an injury
??? - Argina's first fire dragon (CnR KM)

Wind
Carefree and spirited
Milieu - Marciel's adoptive elder brother. He inherited the title of the Wind Dragon Mage from his mother when she went traveling around the world to find her husband. Good friends with Wilf and Kadio, who shares the same birthday date with him. He used to yearn to go out and see the outside world when he was young.
Jen - Sata's elder sister. Very cheerful.
Rottaruku - Prefers everyone to call her Roku. Named after an ancient Wind dragon king. Is still angry at Milieu for giving her a boyish name.
Gureisu
Zein
Others:
Ekaterina – Ex wind dragon mage. Milieu's mother. Husband cannot enter Corseltel as he is not a dragon mage, so she gave her position to her son and left to find her husband. Brought back Marciel to be Milieu's brother, and Kadio to be Milieu's friend.
Fuana - Milieu's baby sister who later visits Corseltel
??? - Milieu's father who doesn't recognise him
Melsh - Milieu's grandmother
Solia - Ekaterina's trainee dragon mage

Dark
Dark dragons seem to worry a lot, even in the past.
Meria – Dark dragon mage. A granny motherly figure, mother to Wilf. Was a demon mage. Brought her son to Corseltel after her husband died.
Raruka - She cares/ worries much for her brother.
Erize - She yearns much to find out about the dark dragon's ancestral home, which is somewhere in space. She intends to return there someday. Had second thoughts after getting to know Rorby.
Wilf (Postman) – Meria's son. Inherited monster magics from parents, useful to his job as a postman. Hides third eye and horn with hat. Worries the dark dragons by not coming home often.
Others:
??? - Meria's husband
??? - New dark dragon mage (CnR KM)
??? - New dark dragon mage's first dragon, a grey dark dragon

Water
Can walk on water, move about in water, breathe in water. They also live on a waterfall.
Elle - Don't get her drunk. She is good with handling swords, and was from the water spirit kingdom before it was destroyed by invaders. Likes Milieu? and Kadio?
Lyric - Likes girls, great at chores as Elle is bad at looking after the house
Kurara – Likes Olta
Rati
Tiruku
Others:
??? - Elle's sister

Wood
Kadio – Was a spirit mage, from same village as Marciel. Is Marciel's uncle. Blames himself for causing a flood while trying to bring rains. Brought to Corseltel by Ekaterina to be Milieu's friend as both have same birthday. Is slightly more mature than Millieu.
Roi – Wants to built a secret base to research interesting wood dragon magics.
Noi – Likes people with great ambition.
Roi and Noi – Both are pranksters, often researching “weird” wood dragon magics or plants which cause trouble to others. Betrothed to each other by the wood dragon tribe leaders.
Kini
Karana
Lotto

Light
Morin – Light dragon mage. Very calm compared to her husband.
Raselt - Brother of the leader of the light dragon tribe, he fell in love with Morin and married her. He tends to overreact.
Maryelle - has a crush on Lyric.
Fariru
Seyuuru

Other dragons:
Siolia - wind dragon tribe leader
Noushe - Previous earth dragon mage's trainee dragon, now the second in command of the earth dragon tribe.
Raydil - Previous fire dragon mage's trainee dragon
Kuruya – Previous wood dragon mage's trainee dragon. Has something against Tata

Others:
Beastman tribe:
Aida - One of the children from the beastmen tribe. He is the leader of the group.
Jili - One of the children from the beastmen tribe. He wears a hat.
Zate - One of the children from the beastmen tribe.
Granny Fure (Fuluadelle) - Helps to care for the baby dragons when Marciel is away. She is an old friend of the winter army's general. She seems to had lived together with him at her house by the lake in the past, before he had to return back to his hometown.

Entotto - From the Tafu tribe. He takes care of a wood spirit, Runtatta.
Runtatta - wood spirit
Rintette – Spirit from the human realms

Seasonal spirits:
Kashi - From the winter army, came to Corseltel just to challenge Marciel, whom he thought was the strongest in Corseltel. He stayed behind when Marciel refused to accept his challenge on the grounds that his dragons are still babies. Now, he is helping Granny Fure with heavy chores while waiting for the baby dragons to grow up.
??? - Kashi's siblings
??? - Kashi's grandmother. Was his lover in the past, but Kashi split into 4 after his long sleep and doesn't remember her. She looks after him like her own child/ grandchild instead.
Puna - Winter spirit with a crush on Kashi.
Naila - Another challenger form the winter army.
Akutaeon – Summer spirit who challenged Kashi

Firuri (Former Dragon King's Dragon Mage) - She was a Yuan dragon mage, and has died. Her coffin is located in Marciel's tree house's basement. She is very cheerful and friendly to the baby dragons. The past dragon king, according to her, is a fun loving dark dragon. (Cue the baby dragons looking at Nata in disbelief)
Azetto - Firuri's dragon, the dark dragon king
Rashe - Firuri's daughter
Doug - Firuri's husband
Craybelle - the spirit Kata met 
Adelisa - the winter spirit granny whom Kashi respects a lot

Ross Aruba (Monster from Monster Army) - When the monsters attacked Corseltel in the past, the dragon mages cause the land to collaspe upon them. This monster was trapped in the debris and was killed. The monsters from other places started sending him letters often after they found out about his plight, which he enjoys reading. Currently, he is living peacefully together with the Former Dragon King's Dragon Mage.

Others:

El'Lenis: eru reneisu/el'reneece?
Lobata(v3, pg 17): ronbaruta/Ronbalta
Niyajisi (tribe): Niakisu/Niakis