Lon

Lon was the Manussan heir to the title of "Federator" when he encountered the Fifth Doctor, Tegan Jovanka and Nyssa. His mother, Tanha, struggled to make him understand the weight of responsibility attached to being, effectively, a prince, but he was largely indifferent towards his destiny. Worse, he showed no interest in his people's history, despite repeated attempts by Ambril, a kind of "court historian", to get him to investigate local sacred caves.

However, when Tegan offered to meet him privately, his ostensible boredom with life temporarily abated. He believed Tegan was making a romantic overture, but as she was under the control of the Mara, she had distinctly different plans. Taking his hand in hers, she brought him under the control of the Mara as well. Lon then began to use his power as "deputy Federator" for the Mara's benefit, which nearly lead to the Mara's successful return. However, the Doctor destroyed the Mara. What repercussions Lon received for his involvement, if any, are unknown. (DW: Snakedance)