Cinder's Faction

Cinder's Faction (unofficial) is a group of antagonists appearing in Volume 2 of RWBY. Members from Volume 1 include Cinder, Roman, and the White Fang. Other than Emerald Sustrai and Mercury Black, the identities of other members of this faction are currently unknown. The details known currently are that Cinder is in charge of three subordinates and the White Fang. Though the extent of her role within this faction is uncertain.

What Cinder's goal is remains to be seen, but her methods are clearly brutal as seen in the fact that her protégés, Emerald and Mercury, happily killed a former member of the White Fang when they learned he was trying to leave for Vacuo. Whatever her agenda, it seemed to entail the collection of Dust as Roman had used his acquisition of the material to excuse the fact that he hadn't dealt with Tukson personally. However, as of the start of Volume 2, Dust seems to no longer be part of the equation.

The Volume 2 Trailer shows Roman and an unidentified girl with two-toned hair unveiling a stolen Atlesian Paladin to the White Fang. The mech is even emblazoned with the White Fang's symbol.

White Fang
It is seen Best Day Ever that the White Fang are clearly working under Cinder's direct orders.

Trivia

 * When Emerald and Mercury's names were finally released, the first assumption was that they, together with Cinder and Roman, would be named Team CREM (cream). Another popular arrangement is CRME which is typically read as crime (not a color) but the abbreviation could also be read as chrome which can denote a reflective silver.
 * When Emerald's surname was revealed, the team name became workable as CRMS (crimson in allusion to Cinder's fan-made alias created at the start of Volume 1).
 * As Monty has said Emerald and Mercury come from other team(s), most fans have since given up finding a common thread to rationalize Cinder's Faction as a team.
 * The Volume 2 Opening seems to indicate that the "Three Bears" are somehow in league with Cinder as well.