A former Borg drone, once Two of Nine, whose mental link with two fellow survivors led them to seek out Seven of Nine aboard Voyager.
Lansor is one of the three former drones from Seven of Nine's old unimatrix who appear in Survival Instinct. As Two of Nine, he survived the crash of their Borg scout ship alongside Seven and the others, and the imperfect removal of their implants left his mind linked to those of Marika Willkarah and P'Chan.
The three try to forcibly join Seven to their link in order to learn what happened after the crash. Once the truth is revealed, Seven decides the Doctor should sever the connection, even though the procedure leaves the three with only about a month to live. Lansor chooses to spend that time exploring the Markonian Outpost.