Yuta

From Memory Alpha, the free Star Trek reference

Yuta was a servant to Sovereign Marouk, leader of the Acamarians. Yuta was a member of the clan Tralesta, the last surviving member of that clan following its decimation by the Lornak clan nearly 100 years prior. As sole living Trelesta, Yuta was genetically altered to live an unnaturally long life, a life she dedicated to hunting down and eliminating all members of the clan responsible for the death of the Tralesta. In addition to her altered lifespan, Yuta's very touch had been altered to transmit a microvirus that would be immediately lethal to anyone who carried the DNA of the Lornak.

In 2366, when Marouk met with Chorgan, leader of the Gatherers and a Lornak, Yuta planned on killing him. She was stopped by Commander Riker, who was forced to kill her to prevent the murder. (TNG: "The Vengeance Factor")