No one knows how or where the Slayer class began. We can only guess at our roots using documents found in the Guild Guide for it is known to be the most reliable story of our history.
"Before the Genesis War, Manoa was an earthly paradise. The gods and their worshippers built a huge temple and they lived in harmony. The Genesis War changed all that. Akene fell into a deep sleep and the gods who followed her were either extinct of disappeared. Manoa became a desert and an enclave for the Witchblades. The magic left behind by the gods drew them in and they began to develop their powers from it. The Dabel Priests called them witches and, not long after, began to hunt them down. Those escaped the Dabel Priests gathered in Manoa, and soon the Witchblades were a force to be reckoned with.
There were the Slayers, using the power of Darkness to destroy their enemies; the Wardens with their power over water; and a third class with access to the spirit of all living beings in Sarad. Though the desert was nearly barren of life, those Witchblades still possessed the warm energy of Sarad within them. It is this energy that they tap into show their enemies how strong they really are.
These Witchblades are agile and delicate, but they are capable of delivering a fierce blow. The grace with which they handle their weapons has earned them the name Bladedancer...(omitted)"
- Treasure Hound Guild Guide, Class Change Chapter 21 Bladedancer -
Though their technique appears gentle, Bladedancers can just as easily bring their blades to the throat of their enemies. Once ostracized and attacked because of their power, they eventually turned to nature for solace and became one with the warm energy of the spirits. They eventually used this power to turn on those who resisted their will and called upon the spirits to destroy their enemies from within. They are adept melee warriors, but they become superior ranged fighters once they learn to harness the power of the spirits.
The Bladedancer is what you might think, they dance with their blades. With many circular motioned attacks and good ability to strike many enemies at once, they dance around their foes, killing them all the while. They are good all around, being good at mobbing, PvP, mobility, etc., though they have few magic-based attacks and no magical range.
They cannot use daggers, Instead, they use two arc blades as weapons. They are specialized in primary attacks, and their attacks cause buffs/debuffs.