Rachel

Rachel is an angel. She was Castiel's lieutenant in the war to win control of heaven against Raphael, who refers to herself as Castiel's friend. She made one brief appearance in "Frontierland".

Season 6
In "Frontierland" Sam and Dean call for Castiel but Rachel instead answers the call. Rachel says that Castiel is busy with the war in heaven. Dean and Rachel keep arguing until Castiel appears and shen then teleports away. Later Rachel summons Castiel to a warehouse. She demands to know if the rumours about "his dirty little secret" are true. Castiel answers and says "I have to defeat to Raphael" and that he has no choice. Rachel then attacks him and the two get into a fight and Castiel kills Rachel.

Demonstrated Powers
Rachel has only demonstrated the ability to teleport. It can be assumed that she has all the normal angel abilities.