Vess

The Vess were a robotic species who excelled at war. They designed and sold arms to war-like races such as the Sontarans, the Cybermen and the Daleks.

They kept a weapons factory in a pocket dimension powered by energy drawn from the Big Bang, where they sold weapons to delegations of prospective buyers. They did business with the Time Lords.

They sold the Decayed Master a conceptual bomb. (AUDIO: The Light at the End)