Dark Ones

The Dark Ones, or Clan of Darkness in the English dub version, are a clan of shinigami that were exiled over 1000 years ago. They took refuge in the Dangai Precipice World and later in the Valley of Screams. Their leader, Ganryū, planned revenge against the Soul Society by finding the Shinenju and using it to collapse Soul Society and the Human world together.

Members
The Clan of Darkness is made up of six members including Ganryū the leader who also calls himself the "Dark One" in the English dub movie. The other five include four men and one woman all of whom were soundly defeated by the Shinigami. The members names are as follows:

Ganryū - The leader of the Dark Ones. Killed by Ichigo Kurosaki after a long battle.

Jai - Is the dark skinned member of the clan, he was killed by Byakuya Kuchiki.

Benin - The only female of the clan, she was killed by Soifon.

Riyan - Is the member of the clan with what appears to be two rocket packs on his back, he was killed by Tōshirō Hitsugaya.

Bau - Is a large man having his face completely covered by a vial and caring two large weapons, he was killed by Renji Abarai.

Mue - Is a small pale clan member who is faces off against Kenpachi Zaraki and killed by him.

Powers
While it is not known if the Clan wielded Zanpakutō or just had unusual weapons as it was never stated, they did display unique powers involving the blanks. Apparently they could use the blank souls to replenish their weapons, create new ones and even regrow limbs.