Trave

 was a Time Lord who was part of Celestial Intervention Agency, and was part of the war against Omega.

She was tasked with killing Ace and Narvin. After the timelines were changed she was tasked with guarding the border between Monan Host and Gallifreyan space. She was shot by Gaal after he was found out to be a traitor. She regenerated into a male form. He then discovered Ace's dead body floating about in space. (AUDIO: Enemy Lines)