The Elites was a battalion of Daleks were equal to the Cult of Skaro. They were shock troops and proved devastatig during the Time War. The commanders of the Elites were marked by their black domes and they were usually the Emperor's guards. Other Elites simply looked like ordinary Dalek soldiers. Many Elites fought during the Battle of Canary Wharf but were then sucked back into the Void by Rose Tyler. When Dalek Caan saved Davros during the Time War, the Elites were sent to protect Caan on his way into battle. They then resumed their duties in combat.
The idea of the Reality Bomb was an invention of the Elites who had managed to extract memories from the deranged Dalek Caan and had found it as an imagination of the Cult of Skaro. They presented the idea to the Supreme Dalek, who gave permission for the plan for 'maximum extermination' to be proceed. During the Dalek invasion of Earth, the Elites led the assault and shot down the Valiant. It was an Elite that shot the Doctor as he ran towards Rose Tyler. The Elites were all but destroyed with the defeat of the Daleks. BUT THEY WILL RETURN! THE DALEKS ALWAYS DO!