Sec

Sec was the leader of the Cult of Skaro and the Dalek responsible for an invasion of Earth in 2007. Encased in a fearsome black design, Sec nearly succeeded in conquering Earth and destroying the Cybermen. Despite the Tenth Doctor's meddling and the eventual destruction of the Dalek army, Sec escaped via a time shift. The other members of the Cult of Skaro were presumably sucked into the Void, along with the Dalek army and the Cybermen.