The "axis of dark powers", a name used to describe the group by the Squire, was the collection of allies the Dalek Empire led into battle during the Last Great Time War. (COMIC: Pull to Open) The Time Lords identified a secondary command structure in the Dalek hierarchy, which was composed of non-Daleks. (PROSE: Dalek Combat Training Manual)
Even though the Dalek Time Strategist proclaimed that the Daleks had no need for allies, saying as such while rejecting an alliance with the Sontaran Empire, (AUDIO: The Eternity Cage) the Daleks did indeed make alliances (AUDIO: The Innocent) and conscript other species during the conflict. (AUDIO: Dreadshade) Nonetheless, these allies and pawns were always exterminated when their usefulness was fulfilled, as the Daleks saw themselves as the supreme beings of the the universe. (PROSE: Engines of War, et al.)