Orlo (Martha in the Mirror)

You may be looking for Orlo (Wetworld).

General Orlo was a Zerugian who, as a gift, gave a duplicate of the Mortal Mirror to mark the beginning of the negotiations. The Tenth Doctor soon found out though, that the Mortal Mirror copy was the original mirror itself. General Orlo was obviously planning something and everything became true at the peace treaty. An army of Zerugians appeared, along with duplicates, from within the mirror. He didn't want peace. He wanted Castle Extremis, which had been owned originally by Anthium. He was killed by Lady Casaubon, who stabbed him with a piece of glass and then put a glass bullet into his skull. (NSA: Martha in the Mirror)